[PATCH 01/12] import: Move json-fetch to (guix import utils).

[PATCH 01/12] import: Move json-fetch to (guix import utils).

[David Craven]

* guix/import/utils.scm (json-fetch): Move json-fetch from
  (guix import json).
---
 guix/import/cpan.scm  |  1 -
 guix/import/gem.scm   |  1 -
 guix/import/json.scm  | 32 --------------------------------
 guix/import/pypi.scm  |  1 -
 guix/import/utils.scm | 12 ++++++++++++
 5 files changed, 12 insertions(+), 35 deletions(-)
 delete mode 100644 guix/import/json.scm

diff --git a/guix/import/cpan.scm b/guix/import/cpan.scm
index 5b7c475..0769064 100644
--- a/guix/import/cpan.scm
+++ b/guix/import/cpan.scm
@@ -31,7 +31,6 @@
   #:use-module (guix base32)
   #:use-module ((guix download) #:select (download-to-store))
   #:use-module (guix import utils)
-  #:use-module (guix import json)
   #:use-module (guix packages)
   #:use-module (guix derivations)
   #:use-module (gnu packages perl)
diff --git a/guix/import/gem.scm b/guix/import/gem.scm
index fc06b0d..b3a50ac 100644
--- a/guix/import/gem.scm
+++ b/guix/import/gem.scm
@@ -26,7 +26,6 @@
   #:use-module (web uri)
   #:use-module ((guix download) #:prefix download:)
   #:use-module (guix import utils)
-  #:use-module (guix import json)
   #:use-module (guix packages)
   #:use-module (guix upstream)
   #:use-module (guix licenses)
diff --git a/guix/import/json.scm b/guix/import/json.scm
deleted file mode 100644
index c3092a5..0000000
--- a/guix/import/json.scm
+++ /dev/null
@@ -1,32 +0,0 @@
-;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2014 David Thompson <davet@gnu.org>
-;;; Copyright © 2015 Eric Bavier <bavier@member.fsf.org>
-;;;
-;;; This file is part of GNU Guix.
-;;;
-;;; GNU Guix is free software; you can redistribute it and/or modify it
-;;; under the terms of the GNU General Public License as published by
-;;; the Free Software Foundation; either version 3 of the License, or (at
-;;; your option) any later version.
-;;;
-;;; GNU Guix is distributed in the hope that it will be useful, but
-;;; WITHOUT ANY WARRANTY; without even the implied warranty of
-;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-;;; GNU General Public License for more details.
-;;;
-;;; You should have received a copy of the GNU General Public License
-;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
-
-(define-module (guix import json)
-  #:use-module (json)
-  #:use-module (guix utils)
-  #:use-module (guix import utils)
-  #:export (json-fetch))
-
-(define (json-fetch url)
-  "Return an alist representation of the JSON resource URL, or #f on failure."
-  (call-with-temporary-output-file
-   (lambda (temp port)
-     (and (url-fetch url temp)
-          (hash-table->alist
-           (call-with-input-file temp json->scm))))))
diff --git a/guix/import/pypi.scm b/guix/import/pypi.scm
index 343445a..3f24014 100644
--- a/guix/import/pypi.scm
+++ b/guix/import/pypi.scm
@@ -38,7 +38,6 @@
                            . hyphen-package-name->name+version)))
   #:use-module (guix import utils)
   #:use-module ((guix download) #:prefix download:)
-  #:use-module (guix import json)
   #:use-module (guix packages)
   #:use-module (guix upstream)
   #:use-module (guix licenses)
diff --git a/guix/import/utils.scm b/guix/import/utils.scm
index 93cd0f0..d19a6df 100644
--- a/guix/import/utils.scm
+++ b/guix/import/utils.scm
@@ -1,5 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2012, 2013 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2014 David Thompson <davet@gnu.org>
+;;; Copyright © 2015 Eric Bavier <bavier@member.fsf.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -25,6 +27,7 @@
   #:use-module ((guix licenses) #:prefix license:)
   #:use-module (guix utils)
   #:use-module ((guix build download) #:prefix build:)
+  #:use-module (json)
   #:export (factorize-uri
 
             hash-table->alist
@@ -32,6 +35,7 @@
             assoc-ref*
 
             url-fetch
+            json-fetch
             guix-hash-url
 
             string->license
@@ -148,3 +152,11 @@ into a proper sentence and by using two spaces between sentences."
     ;; Use double spacing between sentences
     (regexp-substitute/global #f "\\. \\b"
                               cleaned 'pre ".  " 'post)))
+
+(define (json-fetch url)
+  "Return an alist representation of the JSON resource URL, or #f on failure."
+  (call-with-temporary-output-file
+   (lambda (temp port)
+     (and (url-fetch url temp)
+          (hash-table->alist
+           (call-with-input-file temp json->scm))))))
-- 
2.9.0

[PATCH 02/12] import: Reorder imports in (guix import utils).

[David Craven]

* guix/import/utils.scm (define-module): Reorder imports alphabetically.
---
 guix/import/utils.scm | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/guix/import/utils.scm b/guix/import/utils.scm
index d19a6df..8535841 100644
--- a/guix/import/utils.scm
+++ b/guix/import/utils.scm
@@ -19,15 +19,15 @@
 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
 
 (define-module (guix import utils)
-  #:use-module (ice-9 match)
-  #:use-module (ice-9 regex)
-  #:use-module (srfi srfi-1)
-  #:use-module (guix hash)
   #:use-module (guix base32)
+  #:use-module ((guix build download) #:prefix build:)
+  #:use-module (guix hash)
   #:use-module ((guix licenses) #:prefix license:)
   #:use-module (guix utils)
-  #:use-module ((guix build download) #:prefix build:)
+  #:use-module (ice-9 match)
+  #:use-module (ice-9 regex)
   #:use-module (json)
+  #:use-module (srfi srfi-1)
   #:export (factorize-uri
 
             hash-table->alist
-- 
2.9.0

Re: [PATCH 02/12] import: Reorder imports in (guix import utils).

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> * guix/import/utils.scm (define-module): Reorder imports alphabetically.

OK!  :-)

[PATCH 03/12] import: Move string->license to importers.

[David Craven]

* guix/import/gem.scm (string->license): Move from (guix import utils).
* guix/import/pypi.scm (string->license): Move from (guix import utils).
---
 guix/import/gem.scm   | 13 ++++++++++++-
 guix/import/pypi.scm  | 13 ++++++++++++-
 guix/import/utils.scm |  9 ---------
 3 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/guix/import/gem.scm b/guix/import/gem.scm
index b3a50ac..df6b498 100644
--- a/guix/import/gem.scm
+++ b/guix/import/gem.scm
@@ -28,7 +28,7 @@
   #:use-module (guix import utils)
   #:use-module (guix packages)
   #:use-module (guix upstream)
-  #:use-module (guix licenses)
+  #:use-module ((guix licenses) #:prefix license:)
   #:use-module (guix base32)
   #:use-module (guix build-system ruby)
   #:export (gem->guix-package
@@ -154,6 +154,17 @@ package on RubyGems."
     ;; e.g. "https://rubygems.org/downloads/hashery-2.1.1.gem"
     (substring source-url 31 (string-rindex source-url #\-))))
 
+(define (string->license str)
+  "Convert the string STR into a license object."
+  (match str
+    ("GNU LGPL" license:lgpl2.0)
+    ("GPL" license:gpl3)
+    ((or "BSD" "BSD License") license:bsd-3)
+    ((or "MIT" "MIT license" "Expat license") license:expat)
+    ("Public domain" license:public-domain)
+    ((or "Apache License, Version 2.0" "Apache 2.0") license:asl2.0)
+    (_ #f)))
+
 (define (gem-package? package)
   "Return true if PACKAGE is a gem package from RubyGems."
 
diff --git a/guix/import/pypi.scm b/guix/import/pypi.scm
index 3f24014..60067db 100644
--- a/guix/import/pypi.scm
+++ b/guix/import/pypi.scm
@@ -40,7 +40,7 @@
   #:use-module ((guix download) #:prefix download:)
   #:use-module (guix packages)
   #:use-module (guix upstream)
-  #:use-module (guix licenses)
+  #:use-module ((guix licenses) #:prefix license:)
   #:use-module (guix build-system python)
   #:use-module (gnu packages python)
   #:export (guix-package->pypi-name
@@ -293,6 +293,17 @@ VERSION, SOURCE-URL, HOME-PAGE, SYNOPSIS, DESCRIPTION, and LICENSE."
              (make-pypi-sexp name version release wheel home-page synopsis
                              description license))))))
 
+(define (string->license str)
+  "Convert the string STR into a license object."
+  (match str
+    ("GNU LGPL" license:lgpl2.0)
+    ("GPL" license:gpl3)
+    ((or "BSD" "BSD License") license:bsd-3)
+    ((or "MIT" "MIT license" "Expat license") license:expat)
+    ("Public domain" license:public-domain)
+    ((or "Apache License, Version 2.0" "Apache 2.0") license:asl2.0)
+    (_ #f)))
+
 (define (pypi-package? package)
   "Return true if PACKAGE is a Python package from PyPI."
 
diff --git a/guix/import/utils.scm b/guix/import/utils.scm
index 8535841..b5dcc17 100644
--- a/guix/import/utils.scm
+++ b/guix/import/utils.scm
@@ -38,7 +38,6 @@
             json-fetch
             guix-hash-url
 
-            string->license
             license->symbol
 
             snake-case
@@ -113,15 +112,7 @@ recursively apply the procedure to the sub-list."
   "Return the hash of FILENAME in nix-base32 format."
   (bytevector->nix-base32-string (file-sha256 filename)))
 
-(define (string->license str)
-  "Convert the string STR into a license object."
   (match str
-    ("GNU LGPL" license:lgpl2.0)
-    ("GPL" license:gpl3)
-    ((or "BSD" "BSD License") license:bsd-3)
-    ((or "MIT" "MIT license" "Expat license") license:expat)
-    ("Public domain" license:public-domain)
-    ((or "Apache License, Version 2.0" "Apache 2.0") license:asl2.0)
     (_ #f)))
 
 (define (license->symbol license)
-- 
2.9.0

Re: [PATCH 03/12] import: Move string->license to importers.

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> * guix/import/gem.scm (string->license): Move from (guix import utils).
> * guix/import/pypi.scm (string->license): Move from (guix import utils).

OK!

Eventually someone should check whether they really match the license
names used in Gem and PyPI.

Ludo’.

[PATCH 04/12] import: utils: Add spdx-string->license.

[David Craven]

* guix/import/utils.scm (spdx-string->license): New variable.
---
 guix/import/utils.scm | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/guix/import/utils.scm b/guix/import/utils.scm
index b5dcc17..ca00baf 100644
--- a/guix/import/utils.scm
+++ b/guix/import/utils.scm
@@ -2,6 +2,7 @@
 ;;; Copyright © 2012, 2013 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2014 David Thompson <davet@gnu.org>
 ;;; Copyright © 2015 Eric Bavier <bavier@member.fsf.org>
+;;; Copyright © 2016 Jelle Licht <jlicht@fsfe.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -38,6 +39,7 @@
             json-fetch
             guix-hash-url
 
+            spdx-string->license
             license->symbol
 
             snake-case
@@ -112,7 +114,65 @@ recursively apply the procedure to the sub-list."
   "Return the hash of FILENAME in nix-base32 format."
   (bytevector->nix-base32-string (file-sha256 filename)))
 
+(define (spdx-string->license str)
+  "Convert STR, a SPDX formatted license identifier, to a license object.
+   Return #f if STR does not match any known identifiers."
   (match str
+    ("AGPL-1.0"                    'license:AGPL-1.0)
+    ("AGPL-3.0"                    'license:AGPL-3.0)
+    ("Apache-1.1"                  'license:asl1.1)
+    ("Apache-2.0"                  'license:asl2.0)
+    ("BSL-1.0"                     'license:boost1.0)
+    ("BSD-2-Clause-FreeBSD"        'license:bsd-2)
+    ("BSD-3-Clause"                'license:bsd-3)
+    ("BSD-4-Clause"                'license:bsd-4)
+    ("CC0-1.0"                     'license:cc0)
+    ("CC-BY-SA-4.0"                'license:cc-by-sa4.0)
+    ("CC-BY-SA-3.0"                'license:cc-by-sa3.0)
+    ("CC-BY-3.0"                   'license:cc-by3.0)
+    ("CC-BY-2.0"                   'license:cc-by2.0)
+    ("CDDL-1.0"                    'license:cddl1.0)
+    ("CECILL-C"                    'license:cecill-c)
+    ("Artistic-2.0"                'license:artistic2.0)
+    ("ClArtistic"                  'license:clarified-artistic)
+    ("CPL-1.0"                     'license:cpl1.0)
+    ("EPL-1.0"                     'license:epl1.0)
+    ("MIT"                         'license:expat)
+    ("FTL"                         'license:freetype)
+    ("Giftware"                    'license:giftware)
+    ("GPL-1.0"                     'license:gpl1)
+    ("GPL-1.0+"                    'license:gpl1+)
+    ("GPL-2.0"                     'license:gpl2)
+    ("GPL-2.0+"                    'license:gpl2+)
+    ("GPL-3.0"                     'license:gpl3)
+    ("GPL-3.0+"                    'license:gpl3+)
+    ("ISC"                         'license:isc)
+    ("IJG"                         'license:ijg)
+    ("Imlib2"                      'license:imlib2)
+    ("IPA"                         'license:ipa)
+    ("LGPL-2.0"                    'license:lgpl2.0)
+    ("LGPL-2.0+"                   'license:lgpl2.0+)
+    ("LGPL-2.1"                    'license:lgpl2.1)
+    ("LGPL-2.1+"                   'license:lgpl2.1+)
+    ("LGPL-3.0"                    'license:lgpl3.0)
+    ("MPL-1.0"                     'license:mpl1.0)
+    ("MPL-1.1"                     'license:mpl1.1)
+    ("MPL-2.0"                     'license:mpl2.0)
+    ("MS-PL"                       'license:ms-pl)
+    ("NCSA"                        'license:ncsa)
+    ("OpenSSL"                     'license:openssl)
+    ("OLDAP-2.8"                   'license:openldap2.8)
+    ("QPL-1.0"                     'license:qpl)
+    ("Ruby"                        'license:ruby)
+    ("SGI-B-2.0"                   'license:sgifreeb2.0)
+    ("OFL-1.1"                     'license:silofl1.1)
+    ("Sleepycat"                   'license:sleepycat)
+    ("TCL"                         'license:tcl/tk)
+    ("Vim"                         'license:vim)
+    ("Unlicense"                   'license:unlicense)
+    ("X11"                         'license:x11)
+    ("ZPL-2.1"                     'license:zpl2.1)
+    ("Zlib"                        'license:zlib)
     (_ #f)))
 
 (define (license->symbol license)
-- 
2.9.0

Re: [PATCH 04/12] import: utils: Add spdx-string->license.

[Eric Bavier]

Hello,

SPDX seems to be a more general specification for licenses, but I still 
wonder whether its appropriate for (guix import utils), since its used 
only by the crate importer.

On 2016-09-22 08:18, David Craven wrote:
> * guix/import/utils.scm (spdx-string->license): New variable.
> ---
>  guix/import/utils.scm | 60 
> +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 60 insertions(+)
> 
> diff --git a/guix/import/utils.scm b/guix/import/utils.scm
> index b5dcc17..ca00baf 100644
> --- a/guix/import/utils.scm
> +++ b/guix/import/utils.scm
> @@ -2,6 +2,7 @@
>  ;;; Copyright © 2012, 2013 Ludovic Courtès <ludo@gnu.org>
>  ;;; Copyright © 2014 David Thompson <davet@gnu.org>
>  ;;; Copyright © 2015 Eric Bavier <bavier@member.fsf.org>
> +;;; Copyright © 2016 Jelle Licht <jlicht@fsfe.org>
>  ;;;
>  ;;; This file is part of GNU Guix.
>  ;;;
> @@ -38,6 +39,7 @@
>              json-fetch
>              guix-hash-url
> 
> +            spdx-string->license
>              license->symbol
> 
>              snake-case
> @@ -112,7 +114,65 @@ recursively apply the procedure to the sub-list."
>    "Return the hash of FILENAME in nix-base32 format."
>    (bytevector->nix-base32-string (file-sha256 filename)))
> 
> +(define (spdx-string->license str)
> +  "Convert STR, a SPDX formatted license identifier, to a license 
> object.
> +   Return #f if STR does not match any known identifiers."
>    (match str
> +    ("AGPL-1.0"                    'license:AGPL-1.0)
> +    ("AGPL-3.0"                    'license:AGPL-3.0)

These two don't exist in (guix licenses)

> +    ("Apache-1.1"                  'license:asl1.1)
> +    ("Apache-2.0"                  'license:asl2.0)
> +    ("BSL-1.0"                     'license:boost1.0)
> +    ("BSD-2-Clause-FreeBSD"        'license:bsd-2)
> +    ("BSD-3-Clause"                'license:bsd-3)
> +    ("BSD-4-Clause"                'license:bsd-4)
> +    ("CC0-1.0"                     'license:cc0)
> +    ("CC-BY-SA-4.0"                'license:cc-by-sa4.0)
> +    ("CC-BY-SA-3.0"                'license:cc-by-sa3.0)

Maybe also "cc-by-sa2.0"?

> +    ("CC-BY-3.0"                   'license:cc-by3.0)
> +    ("CC-BY-2.0"                   'license:cc-by2.0)

Maybe numerically sort the cc licenses, like the others?

> +    ("CDDL-1.0"                    'license:cddl1.0)
> +    ("CECILL-C"                    'license:cecill-c)
> +    ("Artistic-2.0"                'license:artistic2.0)
> +    ("ClArtistic"                  'license:clarified-artistic)
> +    ("CPL-1.0"                     'license:cpl1.0)
> +    ("EPL-1.0"                     'license:epl1.0)
> +    ("MIT"                         'license:expat)
> +    ("FTL"                         'license:freetype)
> +    ("Giftware"                    'license:giftware)
> +    ("GPL-1.0"                     'license:gpl1)
> +    ("GPL-1.0+"                    'license:gpl1+)
> +    ("GPL-2.0"                     'license:gpl2)
> +    ("GPL-2.0+"                    'license:gpl2+)
> +    ("GPL-3.0"                     'license:gpl3)
> +    ("GPL-3.0+"                    'license:gpl3+)
> +    ("ISC"                         'license:isc)
> +    ("IJG"                         'license:ijg)
> +    ("Imlib2"                      'license:imlib2)
> +    ("IPA"                         'license:ipa)
> +    ("LGPL-2.0"                    'license:lgpl2.0)
> +    ("LGPL-2.0+"                   'license:lgpl2.0+)
> +    ("LGPL-2.1"                    'license:lgpl2.1)
> +    ("LGPL-2.1+"                   'license:lgpl2.1+)
> +    ("LGPL-3.0"                    'license:lgpl3.0)
> +    ("MPL-1.0"                     'license:mpl1.0)
> +    ("MPL-1.1"                     'license:mpl1.1)
> +    ("MPL-2.0"                     'license:mpl2.0)
> +    ("MS-PL"                       'license:ms-pl)
> +    ("NCSA"                        'license:ncsa)
> +    ("OpenSSL"                     'license:openssl)
> +    ("OLDAP-2.8"                   'license:openldap2.8)
> +    ("QPL-1.0"                     'license:qpl)
> +    ("Ruby"                        'license:ruby)
> +    ("SGI-B-2.0"                   'license:sgifreeb2.0)
> +    ("OFL-1.1"                     'license:silofl1.1)
> +    ("Sleepycat"                   'license:sleepycat)
> +    ("TCL"                         'license:tcl/tk)
> +    ("Vim"                         'license:vim)

Alphabetically "vim" succeeds" "unlicense".

> +    ("Unlicense"                   'license:unlicense)
> +    ("X11"                         'license:x11)
> +    ("ZPL-2.1"                     'license:zpl2.1)
> +    ("Zlib"                        'license:zlib)
>      (_ #f)))
> 
>  (define (license->symbol license)

Some that are missing(?):

"IPL-1.0" => 'license:ibmpl1.0
"CUA-OPL-1.0" => 'license:opl1.0
The "psfl" license.  It appears our "psfl" doesn't seem to map cleanly 
to one in the SPDX list.

-- 
`~Eric

Re: [PATCH 04/12] import: utils: Add spdx-string->license.

[David Craven]

Hi,

> SPDX seems to be a more general specification for licenses, but I still
> wonder whether its appropriate for (guix import utils), since its used
> only by the crate importer.

The npm metadata also uses spdx identifiers.

> Maybe also "cc-by-sa2.0"?

Don't know you tell me :) I copied this from a gist that Jelle
published on the ML.

> Maybe numerically sort the cc licenses, like the others?
> Alphabetically "vim" succeeds" "unlicense".

> Some that are missing(?):
>
> "IPL-1.0" => 'license:ibmpl1.0
> "CUA-OPL-1.0" => 'license:opl1.0

Sounds good.

> The "psfl" license.  It appears our "psfl" doesn't seem to map cleanly to
> one in the SPDX list.

I'll add it to guix licenses.

Thanks,
David

Re: [PATCH 04/12] import: utils: Add spdx-string->license.

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> * guix/import/utils.scm (spdx-string->license): New variable.

Eric wrote:

> SPDX seems to be a more general specification for licenses, but I
> still wonder whether its appropriate for (guix import utils), since
> its used only by the crate importer.

The generality is enough to put it here IMO, and npm appears to be using
it like David wrote.

> +(define (spdx-string->license str)
> +  "Convert STR, a SPDX formatted license identifier, to a license object.
                     ^^
Could you add the URL of the SPDX spec somewhere here?

> +   Return #f if STR does not match any known identifiers."
   ^^^
Extra space.

Otherwise LGTM, thanks!

Ludo’.

[PATCH 05/12] import: utils: Refactor license->symbol.

[David Craven]

* guix/import/utils.scm (license->symbol): Work for all licenses.
* tests/import-utils.scm (license->symbol): Add test.
---
 guix/import/utils.scm  | 14 +++++---------
 tests/import-utils.scm |  5 +++++
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/guix/import/utils.scm b/guix/import/utils.scm
index ca00baf..8dab72a 100644
--- a/guix/import/utils.scm
+++ b/guix/import/utils.scm
@@ -3,6 +3,7 @@
 ;;; Copyright © 2014 David Thompson <davet@gnu.org>
 ;;; Copyright © 2015 Eric Bavier <bavier@member.fsf.org>
 ;;; Copyright © 2016 Jelle Licht <jlicht@fsfe.org>
+;;; Copyright © 2016 David Craven <david@craven.ch>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -178,15 +179,10 @@ recursively apply the procedure to the sub-list."
 (define (license->symbol license)
   "Convert license to a symbol representing the variable the object is bound
 to in the (guix licenses) module, or #f if there is no such known license."
-  ;; TODO: Traverse list public variables in (guix licenses) instead so we
-  ;; don't have to maintain a list manualy.
-  (assoc-ref `((,license:lgpl2.0 . license:lgpl2.0)
-               (,license:gpl3 . license:gpl3)
-               (,license:bsd-3 . license:bsd-3)
-               (,license:expat . license:expat)
-               (,license:public-domain . license:public-domain)
-               (,license:asl2.0 . license:asl2.0))
-             license))
+  (define licenses
+    (module-map (lambda (sym var) `(,(variable-ref var) . ,sym))
+                (resolve-interface '(guix licenses) #:prefix 'license:)))
+  (assoc-ref licenses license))
 
 (define (snake-case str)
   "Return a downcased version of the string STR where underscores are replaced
diff --git a/tests/import-utils.scm b/tests/import-utils.scm
index 3b11875..8d44b9e 100644
--- a/tests/import-utils.scm
+++ b/tests/import-utils.scm
@@ -20,6 +20,7 @@
 (define-module (test-import-utils)
   #:use-module (guix tests)
   #:use-module (guix import utils)
+  #:use-module ((guix licenses) #:prefix license:)
   #:use-module (srfi srfi-64))
 
 (test-begin "import-utils")
@@ -33,4 +34,8 @@
   "This package provides a function to establish world peace"
   (beautify-description "A function to establish world peace"))
 
+(test-equal "license->symbol"
+  'license:lgpl2.0
+  (license->symbol license:lgpl2.0))
+
 (test-end "import-utils")
-- 
2.9.0

Re: [PATCH 05/12] import: utils: Refactor license->symbol.

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> * guix/import/utils.scm (license->symbol): Work for all licenses.
> * tests/import-utils.scm (license->symbol): Add test.

OK!

[PATCH 06/12] import: Add importer for rust crates.

[David Craven]

* guix/import/crate.scm (crate-fetch, make-crate-sexp,
  crate->guix-package, guix-package->crate-name, string->license,
  crate-name->package-name): New variables.
* guix/scripts/import/crate.scm (%default-options, show-help, %options,
  guix-import-crate): New variables.
* guix/scripts/import.scm (importers): Add crate to list of importers.
* tests/crate.scm (test-json, test-source-hash,
  guix-package->crate-name, crate->guix-package): New variables.
---
 guix/import/crate.scm         | 91 +++++++++++++++++++++++++++++++++++++++++
 guix/scripts/import.scm       |  2 +-
 guix/scripts/import/crate.scm | 94 +++++++++++++++++++++++++++++++++++++++++++
 tests/crate.scm               | 87 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 273 insertions(+), 1 deletion(-)
 create mode 100644 guix/import/crate.scm
 create mode 100644 guix/scripts/import/crate.scm
 create mode 100644 tests/crate.scm

diff --git a/guix/import/crate.scm b/guix/import/crate.scm
new file mode 100644
index 0000000..3cc17f2
--- /dev/null
+++ b/guix/import/crate.scm
@@ -0,0 +1,91 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2016 David Craven <david@craven.ch>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix import crate)
+  #:use-module (gnu packages rust)
+  #:use-module ((guix download) #:prefix download:)
+  #:use-module (guix import utils)
+  #:use-module ((guix licenses) #:prefix license:)
+  #:use-module (guix packages)
+  #:use-module (guix upstream)
+  #:use-module (guix utils)
+  #:use-module (ice-9 match)
+  #:use-module (json)
+  #:use-module (srfi srfi-1)
+  #:export (crate->guix-package
+            guix-package->crate-name))
+
+(define (crate-fetch name)
+  "Return an alist representation of the crates.io metadata for the package NAME,
+or #f on failure."
+  ;; XXX: We want to silence the download progress report, which is especially
+  ;; annoying for 'guix refresh', but we have to use a file port.
+  (call-with-output-file "/dev/null"
+    (lambda (null)
+      (with-error-to-port null
+        (lambda ()
+          (json-fetch (string-append "https://crates.io/api/v1/crates/"
+                                     name)))))))
+
+;; TODO: Import inputs and native-inputs
+(define (make-crate-sexp name version home-page synopsis description license)
+  "Return the `package' s-expression for a rust package with the given NAME,
+VERSION, SOURCE-URL, HOME-PAGE, SYNOPSIS, DESCRIPTION, and LICENSE."
+  (call-with-temporary-output-file
+   (lambda (temp port)
+     (and (url-fetch (crate-uri name version) temp)
+          `(package
+             (name ,(crate-name->package-name name))
+             (version ,version)
+             (source (origin
+                       (method url-fetch)
+                       (uri (crate-uri ,name version))
+                       (file-name (string-append name "-" version ".tar.gz"))
+                       (sha256
+                        (base32
+                         ,(guix-hash-url temp)))))
+             (build-system cargo-build-system)
+             (home-page ,home-page)
+             (synopsis ,synopsis)
+             (description ,(beautify-description description))
+             (license ,(match license
+                         (() #f)
+                         ((license) license)
+                         (_ `(list ,@license)))))))))
+
+(define (crate->guix-package crate-name)
+  "Fetch the metadata for CRATE-NAME from crates.io, and return the
+`package' s-expression corresponding to that package, or #f on failure."
+  (let ((crate (crate-fetch crate-name)))
+    (let ((name (assoc-ref* crate "crate" "name"))
+          (version (assoc-ref* crate "crate" "max_version"))
+          (home-page (assoc-ref* crate "crate" "homepage"))
+          (synopsis (assoc-ref* crate "crate" "description"))
+          (description (assoc-ref* crate "crate" "description"))
+          (license (string->license (assoc-ref* crate "crate" "license"))))
+      (make-crate-sexp name version home-page synopsis description license))))
+
+(define (guix-package->crate-name package)
+  "Return the crate NAME of a PACKAGE."
+  (string-join (cdr (string-split (package-name package) #\-)) "-"))
+
+(define (string->license string)
+  (map spdx-string->license (string-split string #\/)))
+
+(define (crate-name->package-name name)
+  (string-append "rust-" name))
diff --git a/guix/scripts/import.scm b/guix/scripts/import.scm
index e54744f..c671686 100644
--- a/guix/scripts/import.scm
+++ b/guix/scripts/import.scm
@@ -73,7 +73,7 @@ rather than \\n."
 ;;; Entry point.
 ;;;
 
-(define importers '("gnu" "nix" "pypi" "cpan" "hackage" "elpa" "gem" "cran"))
+(define importers '("gnu" "nix" "pypi" "cpan" "hackage" "elpa" "gem" "cran" "crate"))
 
 (define (resolve-importer name)
   (let ((module (resolve-interface
diff --git a/guix/scripts/import/crate.scm b/guix/scripts/import/crate.scm
new file mode 100644
index 0000000..4337a0b
--- /dev/null
+++ b/guix/scripts/import/crate.scm
@@ -0,0 +1,94 @@
+
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2014 David Thompson <davet@gnu.org>
+;;; Copyright © 2016 David Craven <david@craven.ch>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix scripts import crate)
+  #:use-module (guix ui)
+  #:use-module (guix utils)
+  #:use-module (guix scripts)
+  #:use-module (guix import crate)
+  #:use-module (guix scripts import)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-11)
+  #:use-module (srfi srfi-37)
+  #:use-module (ice-9 match)
+  #:use-module (ice-9 format)
+  #:export (guix-import-crate))
+
+\f
+;;;
+;;; Command-line options.
+;;;
+
+(define %default-options
+  '())
+
+(define (show-help)
+  (display (_ "Usage: guix import crate PACKAGE-NAME
+Import and convert the crate.io package for PACKAGE-NAME.\n"))
+  (display (_ "
+  -h, --help             display this help and exit"))
+  (display (_ "
+  -V, --version          display version information and exit"))
+  (newline)
+  (show-bug-report-information))
+
+(define %options
+  ;; Specification of the command-line options.
+  (cons* (option '(#\h "help") #f #f
+                 (lambda args
+                   (show-help)
+                   (exit 0)))
+         (option '(#\V "version") #f #f
+                 (lambda args
+                   (show-version-and-exit "guix import crate")))
+         %standard-import-options))
+
+\f
+;;;
+;;; Entry point.
+;;;
+
+(define (guix-import-crate . args)
+  (define (parse-options)
+    ;; Return the alist of option values.
+    (args-fold* args %options
+                (lambda (opt name arg result)
+                  (leave (_ "~A: unrecognized option~%") name))
+                (lambda (arg result)
+                  (alist-cons 'argument arg result))
+                %default-options))
+
+  (let* ((opts (parse-options))
+         (args (filter-map (match-lambda
+                            (('argument . value)
+                             value)
+                            (_ #f))
+                           (reverse opts))))
+    (match args
+      ((package-name)
+       (let ((sexp (crate->guix-package package-name)))
+         (unless sexp
+           (leave (_ "failed to download meta-data for package '~a'~%")
+                  package-name))
+         sexp))
+      (()
+       (leave (_ "too few arguments~%")))
+      ((many ...)
+       (leave (_ "too many arguments~%"))))))
diff --git a/tests/crate.scm b/tests/crate.scm
new file mode 100644
index 0000000..71b3567
--- /dev/null
+++ b/tests/crate.scm
@@ -0,0 +1,87 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2014 David Thompson <davet@gnu.org>
+;;; Copyright © 2016 David Craven <david@craven.ch>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (test-crate)
+  #:use-module (guix import crate)
+  #:use-module (guix base32)
+  #:use-module (guix hash)
+  #:use-module (guix tests)
+  #:use-module (ice-9 match)
+  #:use-module (srfi srfi-64))
+
+(define test-json
+  "{
+  \"crate\": {
+    \"max_version\": \"1.0.0\",
+    \"name\": \"foo\",
+    \"license\": \"MIT/Apache-2.0\",
+    \"description\": \"summary\",
+    \"homepage\": \"http://example.com\",
+  }
+}")
+
+(define test-source-hash
+  "")
+
+(test-begin "crate")
+
+(test-equal "guix-package->crate-name"
+  "rustc-serialize"
+  (guix-package->crate-name
+   (dummy-package "rust-rustc-serialize")))
+
+(test-assert "crate->guix-package"
+  ;; Replace network resources with sample data.
+  (mock ((guix import utils) url-fetch
+         (lambda (url file-name)
+           (match url
+             ("https://crates.io/api/v1/crates/foo"
+              (with-output-to-file file-name
+                (lambda ()
+                  (display test-json))))
+             ("https://crates.io/api/v1/crates/foo/1.0.0/download"
+              (with-output-to-file file-name
+                (lambda ()
+                  (display "empty file\n")))
+              (set! test-source-hash
+                (call-with-input-file file-name port-sha256)))
+             (_ (error "Unexpected URL: " url)))))
+    (match (crate->guix-package "foo")
+      (('package
+         ('name "rust-foo")
+         ('version "1.0.0")
+         ('source ('origin
+                    ('method 'url-fetch)
+                    ('uri ('crate-uri "foo" 'version))
+                    ('file-name ('string-append 'name "-" 'version ".tar.gz"))
+                    ('sha256
+                     ('base32
+                      (? string? hash)))))
+         ('build-system 'cargo-build-system)
+         ('home-page "http://example.com")
+         ('synopsis "summary")
+         ('description "summary")
+         ('license ('list 'license:expat 'license:asl2.0)))
+       (string=? (bytevector->nix-base32-string
+                  test-source-hash)
+                 hash))
+      (x
+       (pk 'fail x #f)))))
+
+(test-end "crate")
-- 
2.9.0

Re: [PATCH 06/12] import: Add importer for rust crates.

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> * guix/import/crate.scm (crate-fetch, make-crate-sexp,
>   crate->guix-package, guix-package->crate-name, string->license,
>   crate-name->package-name): New variables.
> * guix/scripts/import/crate.scm (%default-options, show-help, %options,
>   guix-import-crate): New variables.
> * guix/scripts/import.scm (importers): Add crate to list of importers.
> * tests/crate.scm (test-json, test-source-hash,
>   guix-package->crate-name, crate->guix-package): New variables.

Woow, great stuff!  Overall this looks almost ready to me.

Make sure to mention this new importer in guix.texi, under “Invoking
guix import”.


[...]

> +(define-module (guix import crate)
> +  #:use-module (gnu packages rust)

Is this package needed?  Maybe for the definition of ‘crate-uri’?  I
think ‘crate-uri’ should rather go to (guix import crate) or (guix
build-system rust) when that exists.

> +(define (crate-fetch name)
> +  "Return an alist representation of the crates.io metadata for the package NAME,
> +or #f on failure."
> +  ;; XXX: We want to silence the download progress report, which is especially
> +  ;; annoying for 'guix refresh', but we have to use a file port.
> +  (call-with-output-file "/dev/null"
> +    (lambda (null)
> +      (with-error-to-port null
> +        (lambda ()
> +          (json-fetch (string-append "https://crates.io/api/v1/crates/"
> +                                     name)))))))

I don’t really like ‘json-fetch’ because it creates a temporary file,
writes progress report info, etc. (there are cases where we really need
it, for instance when using mirror:// URLs, though).

What about using (guix http-client):

  (let* ((port   (http-fetch …))
         (result (json->scm port)))
    (close-port port)
    (hash-table->alist result))

?

> +;; TODO: Import inputs and native-inputs
> +(define (make-crate-sexp name version home-page synopsis description license)
> +  "Return the `package' s-expression for a rust package with the given NAME,
> +VERSION, SOURCE-URL, HOME-PAGE, SYNOPSIS, DESCRIPTION, and LICENSE."
> +  (call-with-temporary-output-file
> +   (lambda (temp port)
> +     (and (url-fetch (crate-uri name version) temp)

Likewise, I’d rather use ‘http-fetch’ and avoid the temporary file.

> +(define (crate->guix-package crate-name)
> +  "Fetch the metadata for CRATE-NAME from crates.io, and return the
> +`package' s-expression corresponding to that package, or #f on failure."
> +  (let ((crate (crate-fetch crate-name)))
> +    (let ((name (assoc-ref* crate "crate" "name"))
> +          (version (assoc-ref* crate "crate" "max_version"))
> +          (home-page (assoc-ref* crate "crate" "homepage"))
> +          (synopsis (assoc-ref* crate "crate" "description"))
> +          (description (assoc-ref* crate "crate" "description"))
> +          (license (string->license (assoc-ref* crate "crate" "license"))))
> +      (make-crate-sexp name version home-page synopsis description license))))

Note for later: In an eventual patch, we should consider using something
like ‘alist-let*’ in (gnu services herd) instead of ‘assoc-ref*’.

> +(define (guix-package->crate-name package)
> +  "Return the crate NAME of a PACKAGE."

Lowercase “name”, and s/a//.

> +  (string-join (cdr (string-split (package-name package) #\-)) "-"))

I’d prefer:

  (match (string-split …)
    (("rust" rest ...)
     (string-join rest "-")))

cdr is evl!  :-)

> --- /dev/null
> +++ b/guix/scripts/import/crate.scm
> @@ -0,0 +1,94 @@
> +

Extra line.  :-)

Could you send an updated patch?

Thank you!

Ludo’.

[PATCH 07/12] import: crate: Add crate updater.

[David Craven]

* guix/import/crate.scm (crate-package?, latest-release,
  %crate-updater): New variables.
* guix/scripts/refresh.scm (%updaters): Add %crate-updater to list of
  updaters.
* guix/upstream.scm (package-update): Use a url from the list when the
  find2 procedure doesn't find a url sig-url pair.
---
 guix/import/crate.scm    | 36 +++++++++++++++++++++++++++++++++++-
 guix/scripts/refresh.scm |  4 +++-
 guix/upstream.scm        |  2 +-
 3 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/guix/import/crate.scm b/guix/import/crate.scm
index 3cc17f2..5b34330 100644
--- a/guix/import/crate.scm
+++ b/guix/import/crate.scm
@@ -28,7 +28,8 @@
   #:use-module (json)
   #:use-module (srfi srfi-1)
   #:export (crate->guix-package
-            guix-package->crate-name))
+            guix-package->crate-name
+            %crate-updater))
 
 (define (crate-fetch name)
   "Return an alist representation of the crates.io metadata for the package NAME,
@@ -89,3 +90,36 @@ VERSION, SOURCE-URL, HOME-PAGE, SYNOPSIS, DESCRIPTION, and LICENSE."
 
 (define (crate-name->package-name name)
   (string-append "rust-" name))
+
+(define (crate-package? package)
+  "Return true if PACKAGE is a Rust crate from crates.io."
+
+  (define (crate-url? url)
+    (string-prefix? "https://crates.io/" url))
+
+  (let ((source-url (and=> (package-source package) origin-uri))
+        (fetch-method (and=> (package-source package) origin-method)))
+    (and (eq? fetch-method download:url-fetch)
+         (match source-url
+           ((? string?)
+            (crate-url? source-url))
+           ((source-url ...)
+            (any crate-url? source-url))))))
+
+(define (latest-release package)
+  "Return an <upstream-source> for the latest release of PACKAGE."
+  (let* ((crate-name (guix-package->crate-name package))
+         (metadata (crate-fetch crate-name))
+         (version (assoc-ref* metadata "crate" "max_version"))
+         (url (crate-uri crate-name version)))
+    (upstream-source
+     (package (package-name package))
+     (version version)
+     (urls (list url)))))
+
+(define %crate-updater
+  (upstream-updater
+   (name 'crates)
+   (description "Updater for crates.io packages")
+   (pred crate-package?)
+   (latest latest-release)))
diff --git a/guix/scripts/refresh.scm b/guix/scripts/refresh.scm
index b00ac98..3cd5223 100644
--- a/guix/scripts/refresh.scm
+++ b/guix/scripts/refresh.scm
@@ -38,6 +38,7 @@
                           %xorg-updater))
   #:use-module (guix import elpa)
   #:use-module (guix import cran)
+  #:use-module (guix import crate)
   #:use-module (guix import hackage)
   #:use-module (guix gnupg)
   #:use-module (gnu packages)
@@ -206,7 +207,8 @@ unavailable optional dependencies such as Guile-JSON."
                  %hackage-updater
                  ((guix import pypi) => %pypi-updater)
                  ((guix import gem) => %gem-updater)
-                 ((guix import github) => %github-updater)))
+                 ((guix import github) => %github-updater)
+                 ((guix import crate) => %crate-updater)))
 
 (define (lookup-updater name)
   "Return the updater called NAME."
diff --git a/guix/upstream.scm b/guix/upstream.scm
index 1815737..ac3f72f 100644
--- a/guix/upstream.scm
+++ b/guix/upstream.scm
@@ -194,7 +194,7 @@ and 'interactive' (default)."
                              (string-suffix? archive-type url))
                            urls
                            (or signature-urls (circular-list #f)))))
-       (let ((tarball (download-tarball store url signature-url
+       (let ((tarball (download-tarball store (if url url (car urls)) signature-url
                                         #:key-download key-download)))
          (values version tarball))))
     (#f
-- 
2.9.0

Re: [PATCH 07/12] import: crate: Add crate updater.

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> * guix/import/crate.scm (crate-package?, latest-release,
>   %crate-updater): New variables.
> * guix/scripts/refresh.scm (%updaters): Add %crate-updater to list of
>   updaters.
> * guix/upstream.scm (package-update): Use a url from the list when the
>   find2 procedure doesn't find a url sig-url pair.

Neat!

> +(define (latest-release package)
> +  "Return an <upstream-source> for the latest release of PACKAGE."
> +  (let* ((crate-name (guix-package->crate-name package))
> +         (metadata (crate-fetch crate-name))
> +         (version (assoc-ref* metadata "crate" "max_version"))
> +         (url (crate-uri crate-name version)))
> +    (upstream-source
> +     (package (package-name package))
> +     (version version)
> +     (urls (list url)))))

So they don’t publish OpenPGP signatures?  :-/

> --- a/guix/upstream.scm
> +++ b/guix/upstream.scm
> @@ -194,7 +194,7 @@ and 'interactive' (default)."
>                               (string-suffix? archive-type url))
>                             urls
>                             (or signature-urls (circular-list #f)))))
> -       (let ((tarball (download-tarball store url signature-url
> +       (let ((tarball (download-tarball store (if url url (car urls)) signature-url

I don’t understand this part, and I suspect it could lead to
inconsistent results where the signature URL doesn’t match the source
URL.

Do you have an example of the problem you experienced?  Since the
problem is probably not specific to Crates, we should probably address
it in a separate patch.

Otherwise LGTM!

Thanks,
Ludo’.

[PATCH 08/12] build-system: Add cargo build system.

[David Craven]

* guix/build-system/cargo.scm (default-cargo, default-rustc,
  %cargo-build-system-modules, cargo-build, lower, cargo-build-system):
  New variables.
* guix/build/cargo-build-system.scm (configure, build, check, install,
  %standard-phases, cargo-build): New variables.
---
 guix/build-system/cargo.scm       | 135 ++++++++++++++++++++++++++++++++++++++
 guix/build/cargo-build-system.scm |  74 +++++++++++++++++++++
 2 files changed, 209 insertions(+)
 create mode 100644 guix/build-system/cargo.scm
 create mode 100644 guix/build/cargo-build-system.scm

diff --git a/guix/build-system/cargo.scm b/guix/build-system/cargo.scm
new file mode 100644
index 0000000..795d3b2
--- /dev/null
+++ b/guix/build-system/cargo.scm
@@ -0,0 +1,135 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2016 David Craven <david@craven.ch>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix build-system cargo)
+  #:use-module (guix search-paths)
+  #:use-module (guix store)
+  #:use-module (guix utils)
+  #:use-module (guix derivations)
+  #:use-module (guix packages)
+  #:use-module (guix build-system)
+  #:use-module (guix build-system gnu)
+  #:use-module (ice-9 match)
+  #:export (cargo-build-system))
+
+(define (default-cargo)
+  "Return the default Cargo package."
+  ;; Lazily resolve the binding to avoid a circular dependency.
+  (let ((rust (resolve-interface '(gnu packages rust))))
+    (module-ref rust 'cargo-bootstrap)))
+
+(define (default-rustc)
+  "Return the default Rustc package."
+  ;; Lazily resolve the binding to avoid a circular dependency.
+  (let ((rust (resolve-interface '(gnu packages rust))))
+    (module-ref rust 'rustc-bootstrap)))
+
+(define %cargo-build-system-modules
+  ;; Build-side modules imported by default.
+  `((guix build cargo-build-system)
+    ,@%gnu-build-system-modules))
+
+(define* (cargo-build store name inputs
+                      #:key
+                      (tests? #t)
+                      (test-target "test")
+                      (configure-flags ''())
+                      (phases '(@ (guix build cargo-build-system)
+                                  %standard-phases))
+                      (outputs '("out"))
+                      (search-paths '())
+                      (system (%current-system))
+                      (guile #f)
+                      (imported-modules %cargo-build-system-modules)
+                      (modules '((guix build cargo-build-system)
+                                 (guix build utils))))
+  "Build SOURCE using CARGO, and with INPUTS."
+
+  (define builder
+    `(begin
+       (use-modules ,@modules)
+       (cargo-build #:name ,name
+                    #:source ,(match (assoc-ref inputs "source")
+                                (((? derivation? source))
+                                 (derivation->output-path source))
+                                ((source)
+                                 source)
+                                (source
+                                 source))
+                    #:configure-flags ,configure-flags
+                    #:system ,system
+                    #:test-target ,test-target
+                    #:tests? ,tests?
+                    #:phases ,phases
+                    #:outputs %outputs
+                    #:search-paths ',(map search-path-specification->sexp
+                                          search-paths)
+                    #:inputs %build-inputs)))
+
+  (define guile-for-build
+    (match guile
+      ((? package?)
+       (package-derivation store guile system #:graft? #f))
+      (#f                                         ; the default
+       (let* ((distro (resolve-interface '(gnu packages commencement)))
+              (guile  (module-ref distro 'guile-final)))
+         (package-derivation store guile system #:graft? #f)))))
+
+  (build-expression->derivation store name builder
+                                #:inputs inputs
+                                #:system system
+                                #:modules imported-modules
+                                #:outputs outputs
+                                #:guile-for-build guile-for-build))
+
+(define* (lower name
+                #:key source inputs native-inputs outputs system target
+                (cargo (default-cargo))
+                (rustc (default-rustc))
+                #:allow-other-keys
+                #:rest arguments)
+  "Return a bag for NAME."
+
+  (define private-keywords
+    '(#:source #:target #:cargo #:rustc #:inputs #:native-inputs))
+
+  (and (not target) ;; TODO: support cross-compilation
+       (bag
+         (name name)
+         (system system)
+         (target target)
+         (host-inputs `(,@(if source
+                              `(("source" ,source))
+                              '())
+                        ,@inputs
+
+                        ;; Keep the standard inputs of 'gnu-build-system'
+                        ,@(standard-packages)))
+         (build-inputs `(("cargo" ,cargo)
+                         ("rustc" ,rustc)
+                         ,@native-inputs))
+         (outputs outputs)
+         (build (if target cargo-cross-build cargo-build))
+         (arguments (strip-keyword-arguments private-keywords arguments)))))
+
+(define cargo-build-system
+  (build-system
+    (name 'cargo)
+    (description
+     "Cargo build system, to build Rust crates")
+    (lower lower)))
diff --git a/guix/build/cargo-build-system.scm b/guix/build/cargo-build-system.scm
new file mode 100644
index 0000000..ea70257
--- /dev/null
+++ b/guix/build/cargo-build-system.scm
@@ -0,0 +1,74 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2016 David Craven <david@craven.ch>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix build cargo-build-system)
+  #:use-module ((guix build gnu-build-system) #:prefix gnu:)
+  #:use-module (guix build utils)
+  #:use-module (ice-9 match)
+  #:use-module (ice-9 ftw)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-26)
+  #:export (%standard-phases
+            cargo-build))
+
+;; Commentary:
+;;
+;; Builder-side code of the standard Python package build procedure.
+;;
+;; Code:
+
+(define* (configure #:rest empty)
+  "Replace Cargo.toml [dependencies] section with guix inputs."
+  ;;TODO
+  #t)
+
+(define* (build #:rest empty)
+  "Build a given Cargo package."
+  (zero? (system* "cargo" "build" "--release")))
+
+(define* (check #:rest empty)
+  "Run tests for a given Cargo package."
+  (zero? (system* "cargo" "test")))
+
+(define* (install #:key inputs outputs #:allow-other-keys)
+  "Install a given Cargo package."
+  (let* ((out (assoc-ref outputs "out"))
+         (src (assoc-ref inputs "source"))
+         (bin (string-append out "/bin"))
+         (rsrc (string-append out "/rustsrc")))
+    (mkdir-p rsrc)
+    (copy-recursively "src" (string-append rsrc "/src"))
+    (install-file "Cargo.toml" rsrc)
+    ;; Will fail if crate doesn't contain an executable
+    (system* "cargo" "install" "--root" bin)
+    #t))
+
+(define %standard-phases
+  ;; 'configure' phase is not needed.
+  (modify-phases gnu:%standard-phases
+    (replace 'configure configure)
+    (replace 'build build)
+    (replace 'check check)
+    (replace 'install install)))
+
+(define* (cargo-build #:key inputs (phases %standard-phases)
+                      #:allow-other-keys #:rest args)
+  "Build the given Cargo package, applying all of PHASES in order."
+  (apply gnu:gnu-build #:inputs inputs #:phases phases args))
+
+;;; cargo-build-system.scm ends here
-- 
2.9.0

Re: [PATCH 08/12] build-system: Add cargo build system.

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> * guix/build-system/cargo.scm (default-cargo, default-rustc,
>   %cargo-build-system-modules, cargo-build, lower, cargo-build-system):
>   New variables.
> * guix/build/cargo-build-system.scm (configure, build, check, install,
>   %standard-phases, cargo-build): New variables.

[...]

> +;; Commentary:
> +;;
> +;; Builder-side code of the standard Python package build procedure.

s/Python/Rust/  :-)

> +(define* (configure #:rest empty)
> +  "Replace Cargo.toml [dependencies] section with guix inputs."
> +  ;;TODO

So what would this do?  Do we end up using bundled dependencies if we
don’t do that?

> +(define* (build #:rest empty)
> +  "Build a given Cargo package."
> +  (zero? (system* "cargo" "build" "--release")))

It may be useful to make "--release" configurable, like the #:build-type
of ‘cmake-build-system’.

Also, ‘empty’ is a confusing variable name here, because it’s definitely
a non-empty list; maybe simply ‘rest’ or ‘_’?

> +(define* (check #:rest empty)

Ditto.

> +(define* (install #:key inputs outputs #:allow-other-keys)
> +  "Install a given Cargo package."
> +  (let* ((out (assoc-ref outputs "out"))
> +         (src (assoc-ref inputs "source"))
> +         (bin (string-append out "/bin"))
> +         (rsrc (string-append out "/rustsrc")))
> +    (mkdir-p rsrc)
> +    (copy-recursively "src" (string-append rsrc "/src"))

Why do we need to install the source code?

If it’s really needed for the functioning of the package, I’d suggest
moving it to OUT/share/rust-source/PACKAGE-VERSION or something like
this, no?

> +    (install-file "Cargo.toml" rsrc)
> +    ;; Will fail if crate doesn't contain an executable
> +    (system* "cargo" "install" "--root" bin)

I suppose many crates provides a library and no executable, so it’d be
nice to find what needs to be done here.  Thoughts?

The rest LGTM.

Thank you!

Ludo’.

Re: [PATCH 08/12] build-system: Add cargo build system.

[David Craven]

>> +(define* (configure #:rest empty)
>> +  "Replace Cargo.toml [dependencies] section with guix inputs."
>> +  ;;TODO
>
> So what would this do?  Do we end up using bundled dependencies if we
> don’t do that?

If we don't do that cargo tries to download them from crates.io, and
since it's running in a container, would fail.

>> +(define* (build #:rest empty)
>> +  "Build a given Cargo package."
>> +  (zero? (system* "cargo" "build" "--release")))
>
> It may be useful to make "--release" configurable, like the #:build-type
> of ‘cmake-build-system’.

> Why do we need to install the source code?
>
> If it’s really needed for the functioning of the package, I’d suggest
> moving it to OUT/share/rust-source/PACKAGE-VERSION or something like
> this, no?

Rust doesn't have a fixed ABI yet, so cargo builds everything from
source. There is precedent in other distros (I think debian) and
languages (go).

>> +    (install-file "Cargo.toml" rsrc)
>> +    ;; Will fail if crate doesn't contain an executable
>> +    (system* "cargo" "install" "--root" bin)
>
> I suppose many crates provides a library and no executable, so it’d be
> nice to find what needs to be done here.  Thoughts?

if we replace all dependencies with local ones, this isn't an issue.

Re: [PATCH 08/12] build-system: Add cargo build system.

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

>>> +(define* (configure #:rest empty)
>>> +  "Replace Cargo.toml [dependencies] section with guix inputs."
>>> +  ;;TODO
>>
>> So what would this do?  Do we end up using bundled dependencies if we
>> don’t do that?
>
> If we don't do that cargo tries to download them from crates.io, and
> since it's running in a container, would fail.

OK, fine.

>>> +(define* (build #:rest empty)
>>> +  "Build a given Cargo package."
>>> +  (zero? (system* "cargo" "build" "--release")))
>>
>> It may be useful to make "--release" configurable, like the #:build-type
>> of ‘cmake-build-system’.
>
>> Why do we need to install the source code?
>>
>> If it’s really needed for the functioning of the package, I’d suggest
>> moving it to OUT/share/rust-source/PACKAGE-VERSION or something like
>> this, no?
>
> Rust doesn't have a fixed ABI yet, so cargo builds everything from
> source. There is precedent in other distros (I think debian) and
> languages (go).

So Cargo *rebuilds* dependencies, even if they were built with the exact
same compiler?

In our case it would be great if we could disable that because we can
ensure that we are indeed building using a single compiler.

Thoughts?

>>> +    (install-file "Cargo.toml" rsrc)
>>> +    ;; Will fail if crate doesn't contain an executable
>>> +    (system* "cargo" "install" "--root" bin)
>>
>> I suppose many crates provides a library and no executable, so it’d be
>> nice to find what needs to be done here.  Thoughts?
>
> if we replace all dependencies with local ones, this isn't an issue.

I was referring to the comment above; what happens if we run “cargo
install --root BIN” on a package that does not contains executables?

Thanks,
Ludo’.

[PATCH 09/12] gnu: Add rust-bootstrap-x86_64-1.12.0.

[David Craven]

* gnu/packages/rust.scm (rust-bootstrap-x86_64-1.12.0): New variable.
---
 gnu/packages/rust.scm | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 gnu/packages/rust.scm

diff --git a/gnu/packages/rust.scm b/gnu/packages/rust.scm
new file mode 100644
index 0000000..1831aa7
--- /dev/null
+++ b/gnu/packages/rust.scm
@@ -0,0 +1,30 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2016 Eric Le Bihan <address@hidden>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu packages rust)
+  #:use-module (guix download))
+
+(define rust-bootstrap-x86_64-1.12.0
+  (origin
+    (method url-fetch)
+    (uri (string-append
+          "https://static.rust-lang.org/dist/"
+          "rust-beta-x86_64-unknown-linux-gnu.tar.gz"))
+    (sha256
+     (base32
+      "1is1k93zarvxx0h7b57ga8vr9gj34b36l9la6zkph41x33gfgpvl"))))
-- 
2.9.0

Re: [PATCH 09/12] gnu: Add rust-bootstrap-x86_64-1.12.0.

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> * gnu/packages/rust.scm (rust-bootstrap-x86_64-1.12.0): New variable.

IMO this should go with the next patch (rustc-bootstrap) since it
doesn’t make much sense on its own.

Ludo’.

[PATCH 10/12] gnu: Add rustc-bootstrap.

[David Craven]

* gnu/packages/rust.scm (rustc-bootstrap): New variable.
---
 gnu/packages/rust.scm | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 66 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/rust.scm b/gnu/packages/rust.scm
index 1831aa7..4030d18 100644
--- a/gnu/packages/rust.scm
+++ b/gnu/packages/rust.scm
@@ -17,7 +17,16 @@
 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
 
 (define-module (gnu packages rust)
-  #:use-module (guix download))
+  #:use-module (gnu packages base)
+  #:use-module (gnu packages bootstrap)
+  #:use-module (gnu packages commencement)
+  #:use-module (gnu packages compression)
+  #:use-module (gnu packages elf)
+  #:use-module (gnu packages gcc)
+  #:use-module (guix build-system trivial)
+  #:use-module (guix download)
+  #:use-module (guix packages)
+  #:use-module ((guix licenses) #:prefix license:))
 
 (define rust-bootstrap-x86_64-1.12.0
   (origin
@@ -28,3 +37,59 @@
     (sha256
      (base32
       "1is1k93zarvxx0h7b57ga8vr9gj34b36l9la6zkph41x33gfgpvl"))))
+
+(define-public rustc-bootstrap
+  (package
+    (name "rustc-bootstrap")
+    (version "1.12.0")
+    (source rust-bootstrap-x86_64-1.12.0)
+    (build-system gnu-build-system)
+    (native-inputs
+     `(("patchelf" ,patchelf)))
+    (inputs
+     `(("gcc-lib" ,gcc "lib")
+       ("gcc-toolchain-6" ,gcc-toolchain-6)
+       ("zlib" ,zlib)))
+    (arguments
+     `(#:tests? #f
+       #:strip-binaries? #f
+       #:phases
+       (modify-phases %standard-phases
+         (delete 'configure)
+         (delete 'build)
+         (replace 'install
+           (lambda* (#:key inputs outputs #:allow-other-keys)
+             (let ((out (assoc-ref outputs "out"))
+                   (gcc-lib (assoc-ref inputs "gcc-lib"))
+                   (toolchain (assoc-ref inputs "gcc-toolchain-6"))
+                   (zlib (assoc-ref inputs "zlib"))
+                   (platform ,(system->rust-platform (%current-system)))
+                   (ld-so (string-append (assoc-ref inputs "libc")
+                                         ,(glibc-dynamic-linker))))
+               (system* "bash" "install.sh"
+                        (string-append "--prefix=" out)
+                        (string-append "--components=rustc,"
+                                       "rust-std-" platform))
+               (for-each
+                (lambda (file)
+                  (system* "patchelf"
+                           "--set-rpath"
+                           (string-append out "/lib:" zlib "/lib:"
+                                          gcc-lib "/lib:" toolchain "/lib")
+                           file))
+                (cons* (string-append out "/bin/rustc")
+                       (string-append out "/bin/rustdoc")
+                       (find-files out "\\.so$")))
+               (for-each
+                (lambda (file)
+                  (system* "patchelf"
+                           "--set-interpreter" ld-so
+                           file))
+                (list (string-append out "/bin/rustc")
+                      (string-append out "/bin/rustdoc")))
+               (symlink (string-append toolchain "/bin/gcc")
+                        (string-append out "/bin/cc"))))))))
+    (home-page "https://www.rust-lang.org")
+    (synopsis "Rustc bootstrap")
+    (description "Rustc bootstrap.")
+    (license license:asl2.0)))
-- 
2.9.0

Re: [PATCH 10/12] gnu: Add rustc-bootstrap.

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> * gnu/packages/rust.scm (rustc-bootstrap): New variable.

[...]

> +(define-public rustc-bootstrap
> +  (package
> +    (name "rustc-bootstrap")
> +    (version "1.12.0")
> +    (source rust-bootstrap-x86_64-1.12.0)

Could you add a comment above that summarizes the bootstrapping story
that Eric Le Bihan and others discussed about here, and/or give a link
to that discussion?

> +    (inputs
> +     `(("gcc-lib" ,gcc "lib")
> +       ("gcc-toolchain-6" ,gcc-toolchain-6)

I think we can omit “-6” and use the current default.  However could you
add a comment as to why we depend on gcc-toolchain and provide that “cc”
symlink?  I’m sure Eric L.B. explained it before, but I forgot.

> +                   (platform ,(system->rust-platform (%current-system)))

I don’t see ‘system->rust-platform’ defined here.  I think it’d be best
in the importer or in the build system.

> +    (description "Rustc bootstrap.")

Could you expound a bit?

Thanks for picking it up!

Ludo’.

[PATCH 11/12] gnu: Add cargo-bootstrap.

[David Craven]

* gnu/packages/rust.scm (cargo-bootstrap): New variable.
---
 gnu/packages/rust.scm | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/gnu/packages/rust.scm b/gnu/packages/rust.scm
index 4030d18..33c1d5c 100644
--- a/gnu/packages/rust.scm
+++ b/gnu/packages/rust.scm
@@ -93,3 +93,43 @@
     (synopsis "Rustc bootstrap")
     (description "Rustc bootstrap.")
     (license license:asl2.0)))
+
+(define-public cargo-bootstrap
+  (package
+    (name "cargo-bootstrap")
+    (version "1.12.0")
+    (source rust-bootstrap-x86_64-1.12.0)
+    (build-system gnu-build-system)
+    (native-inputs
+     `(("patchelf" ,patchelf)))
+    (inputs
+     `(("gcc-lib" ,gcc "lib")
+       ("gcc-toolchain-6" ,gcc-toolchain-6)))
+    (arguments
+     `(#:tests? #f
+       #:strip-binaries? #f
+       #:phases
+       (modify-phases %standard-phases
+         (delete 'configure)
+         (delete 'build)
+         (replace 'install
+           (lambda* (#:key inputs outputs #:allow-other-keys)
+             (let ((out (assoc-ref outputs "out"))
+                   (platform ,(system->rust-platform (%current-system)))
+                   (ld-so (string-append (assoc-ref inputs "libc")
+                                         ,(glibc-dynamic-linker))))
+               (system* "bash" "install.sh"
+                        (string-append "--prefix=" out)
+                        "--components=cargo")
+               (zero? (system* "patchelf"
+                               "--set-interpreter" ld-so
+                               "--set-rpath"
+                               (string-append
+                                out "/lib:"
+                                (assoc-ref inputs "gcc-lib") "/lib:"
+                                (assoc-ref inputs "gcc-toolchain-6") "/lib")
+                      (string-append out "/bin/cargo")))))))))
+    (home-page "https://www.rust-lang.org")
+    (synopsis "Cargo bootstrap")
+    (description "Cargo bootstrap.")
+    (license license:asl2.0)))
-- 
2.9.0

Re: [PATCH 11/12] gnu: Add cargo-bootstrap.

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> * gnu/packages/rust.scm (cargo-bootstrap): New variable.

So I gather that Cargo cannot be built at all with a build tool other
than Cargo, right?

> +(define-public cargo-bootstrap
> +  (package
> +    (name "cargo-bootstrap")
> +    (version "1.12.0")
> +    (source rust-bootstrap-x86_64-1.12.0)
> +    (build-system gnu-build-system)
> +    (native-inputs
> +     `(("patchelf" ,patchelf)))
> +    (inputs
> +     `(("gcc-lib" ,gcc "lib")
> +       ("gcc-toolchain-6" ,gcc-toolchain-6)))

s/-6//

> +    (description "Cargo bootstrap.")

Please expound.  :-)

Otherwise LGTM, thanks!

Ludo’.

[PATCH 12/12] gnu: Add rust helper functions.

[David Craven]

* gnu/packages/rust.scm (crate-uri, system->rust-platform): New
  variables.
---
 gnu/packages/rust.scm | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/rust.scm b/gnu/packages/rust.scm
index 33c1d5c..ebb9727 100644
--- a/gnu/packages/rust.scm
+++ b/gnu/packages/rust.scm
@@ -26,7 +26,18 @@
   #:use-module (guix build-system trivial)
   #:use-module (guix download)
   #:use-module (guix packages)
-  #:use-module ((guix licenses) #:prefix license:))
+  #:use-module ((guix licenses) #:prefix license:)
+  #:export (crate-uri))
+
+(define (crate-uri name version)
+  "Return a URI string for the crate package hosted at crates.io corresponding
+to NAME and VERSION."
+  (string-append "https://crates.io/api/v1/crates/" name "/" version "/download"))
+
+(define (system->rust-platform system)
+  (cond
+   ((string-prefix? "x86_64" system) "x86_64-unknown-linux-gnu")
+   ((string-prefix? "i686" system) "i686-unknown-linux-gnu")))
 
 (define rust-bootstrap-x86_64-1.12.0
   (origin
-- 
2.9.0

Re: [PATCH 12/12] gnu: Add rust helper functions.

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> * gnu/packages/rust.scm (crate-uri, system->rust-platform): New
>   variables.

Oh, now I see.  :-)  This patch should come earlier, but as I wrote
before, I’d rather have those procedures in the build system or
importer, to avoid loading all of (gnu packages …) just for them.

Thanks a lot for this big series!

Ludo’.

Re: [PATCH 01/12] import: Move json-fetch to (guix import utils).

[Eric Bavier]

On 2016-09-22 08:18, David Craven wrote:
> * guix/import/utils.scm (json-fetch): Move json-fetch from
>   (guix import json).
> ---
>  guix/import/cpan.scm  |  1 -
>  guix/import/gem.scm   |  1 -
>  guix/import/json.scm  | 32 --------------------------------
>  guix/import/pypi.scm  |  1 -
>  guix/import/utils.scm | 12 ++++++++++++
>  5 files changed, 12 insertions(+), 35 deletions(-)
>  delete mode 100644 guix/import/json.scm

We can't do this, since guile-json is an optional dependency for Guix.  
See the manual and makefiles.

`~Eric

Re: [PATCH 01/12] import: Move json-fetch to (guix import utils).

[David Craven]

> guile-json is an optional dependency for Guix.  See
> the manual and makefiles.

I see, didn't know.

> We can't do this

I'm not sure that this is correct.

From the manual:
> Installing Guile-JSON will allow you to use the guix
> import pypi command (see Section 6.5 [Invoking guix
> import], page 75). It is of interest primarily for
> developers and not for casual users.

CPAN, GEM and CARGO importers also use guile-json. If
a developer is using importers I think he can install guile-json
since most importers use it. (guix import utils) is only used
by importers, so people that don't want to use importers
can continue without using guile-json. To put it in perspective
guile-json is 100KB (guix size only displays MB).

Re: [PATCH 01/12] import: Move json-fetch to (guix import utils).

[Eric Bavier]

On 2016-09-22 10:23, David Craven wrote:
>> guile-json is an optional dependency for Guix.  See
>> the manual and makefiles.
> 
> I see, didn't know.
> 
>> We can't do this
> 
> I'm not sure that this is correct.
> 
> From the manual:
>> Installing Guile-JSON will allow you to use the guix
>> import pypi command (see Section 6.5 [Invoking guix
>> import], page 75). It is of interest primarily for
>> developers and not for casual users.
> 
> CPAN, GEM and CARGO importers also use guile-json. If
> a developer is using importers I think he can install guile-json
> since most importers use it. (guix import utils) is only used
> by importers, so people that don't want to use importers
> can continue without using guile-json. To put it in perspective
> guile-json is 100KB (guix size only displays MB).

Overall the patch seems like a net loss.  If guile-json is an optional 
dependency for Guix and there are importers that don't need it (cran, 
hackage, elpa, nix, gnu), then we shouldn't make importers completely 
inaccessible for those who want to use Guix without guile-json so that 
we can gain what?

-- 
`~Eric

Re: [PATCH 01/12] import: Move json-fetch to (guix import utils).

[David Craven]

Just didn't see the point of having a file json.scm file there and
found the name to be a little misleading, but ok.

Re: [PATCH 01/12] import: Move json-fetch to (guix import utils).

[Ludovic Courtès]

David Craven <david@craven.ch> skribis:

> Just didn't see the point of having a file json.scm file there and
> found the name to be a little misleading, but ok.

Yeah, what Eric describes is the reason.  And then (guix scripts
refresh) has this ‘maybe-updater’ macro that checks whether a given
import depends on a missing optional dependency.

Given that JSON is used a lot, we might eventually make Guile-JSON a
mandatory dependency.  We could also push David Thompson to update the
(ice-9 json) module and have it in Guile proper.  :-)

Ludo’.