[bug#51985] lint: Adjust patch file length check.

[bug#51985] lint: Adjust patch file length check.

[Vagrant Cascadian]

[-- Attachment #1.1: Type: text/plain, Size: 703 bytes --]

The current guix lint check is a bit overly conservative, and reports
several results which do not in practice actually cause issues.

This patch proposes to reduce the size by two characters (leaving only
two patches on guix master that need to be adjusted), uses a version
string more like what actually might be included in a tarball built
using "make dist", and adds a comment describing what the arbitrary
string actually is supposed to represent.

This should still even leave a little wiggle-room when guix hits version
100+ and/or 1000000+ commits, by which time hopefully guix has switched
to a tarball format that doesn't have such a short arbitrary file length
limit!


live well,
  vagrant


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1.2: 0001-lint-Adjust-patch-file-length-check.patch --]
[-- Type: text/x-diff, Size: 1154 bytes --]

From 6ad2050a8bbc308a328d30d4f66cb229d868b79d Mon Sep 17 00:00:00 2001
From: Vagrant Cascadian <vagrant@debian.org>
Date: Fri, 19 Nov 2021 12:14:19 -0800
Subject: [PATCH] lint: Adjust patch file length check.

* guix/lint.scm (check-patch-file-names): Adjust margin used to check for
  patch file lengths.
---
 guix/lint.scm | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/guix/lint.scm b/guix/lint.scm
index ac2e7b3841..39b4a2ae85 100644
--- a/guix/lint.scm
+++ b/guix/lint.scm
@@ -957,7 +957,10 @@ patch could not be found."
 
      ;; Check whether we're reaching tar's maximum file name length.
      (let ((prefix (string-length (%distro-directory)))
-           (margin (string-length "guix-2.0.0rc3-10000-1234567890/"))
+           ;; Margin approximating the largest path that "make dist" might
+           ;; create, with a release candidate version, 123456 commits, and
+           ;; git commit hash abcde0.
+           (margin (string-length "guix-12.0.0rc3-123456-abcde0/"))
            (max    99))
        (filter-map (match-lambda
                      ((? string? patch)
-- 
2.30.2


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 227 bytes --]

[bug#51985] lint: Adjust patch file length check.

[Ludovic Courtès]

Hi,

Vagrant Cascadian <vagrant@debian.org> skribis:

> From 6ad2050a8bbc308a328d30d4f66cb229d868b79d Mon Sep 17 00:00:00 2001
> From: Vagrant Cascadian <vagrant@debian.org>
> Date: Fri, 19 Nov 2021 12:14:19 -0800
> Subject: [PATCH] lint: Adjust patch file length check.
>
> * guix/lint.scm (check-patch-file-names): Adjust margin used to check for
>   patch file lengths.

Make sure “make check TESTS=tests/lint.scm” is still happy, but
otherwise LGTM.

Thanks!

Ludo’.

[bug#51985] lint: Adjust patch file length check.

[Vagrant Cascadian]

[-- Attachment #1: Type: text/plain, Size: 1018 bytes --]

On 2021-11-22, Ludovic Courtès wrote:
> Vagrant Cascadian <vagrant@debian.org> skribis:
>> From 6ad2050a8bbc308a328d30d4f66cb229d868b79d Mon Sep 17 00:00:00 2001
>> From: Vagrant Cascadian <vagrant@debian.org>
>> Date: Fri, 19 Nov 2021 12:14:19 -0800
>> Subject: [PATCH] lint: Adjust patch file length check.
>>
>> * guix/lint.scm (check-patch-file-names): Adjust margin used to check for
>>   patch file lengths.
>
> Make sure “make check TESTS=tests/lint.scm” is still happy, but
> otherwise LGTM.

With:

  commit bdf5c16ac052af2ca9d5c3acc4acbc08fd9fdbea
  Author: Ludovic Courtès <ludo@gnu.org>
  Date:   Tue Nov 23 09:06:49 2021 +0100

    maint: "make dist" builds tarballs in 'ustar' format.

It seems like this actually needs even further updates, as that should
allow for a much longer file length in general (although a little
difficult to figure out the exact file length allowed).

And then the corresponding test suite will need changes as well...

live well,
  vagrant

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 227 bytes --]

[bug#51985] lint: Adjust patch file length check.

[Ludovic Courtès]

Hi,

Vagrant Cascadian <vagrant@debian.org> skribis:

> With:
>
>   commit bdf5c16ac052af2ca9d5c3acc4acbc08fd9fdbea
>   Author: Ludovic Courtès <ludo@gnu.org>
>   Date:   Tue Nov 23 09:06:49 2021 +0100
>
>     maint: "make dist" builds tarballs in 'ustar' format.
>
> It seems like this actually needs even further updates, as that should
> allow for a much longer file length in general (although a little
> difficult to figure out the exact file length allowed).
>
> And then the corresponding test suite will need changes as well...

I think independently of the switch to ustar, it’s a good idea for ‘guix
lint’ to warn about long patch file names, but to warn a bit less
frequently than today.

In that spirit, your patch is still relevant and worth applying IMO.

Thoughts?

Ludo’.

[bug#51985] lint: Adjust patch file length check.

[Vagrant Cascadian]

[-- Attachment #1.1: Type: text/plain, Size: 1552 bytes --]

On 2021-11-25, Ludovic Courtès wrote:
> Vagrant Cascadian <vagrant@debian.org> skribis:
>
>> With:
>>
>>   commit bdf5c16ac052af2ca9d5c3acc4acbc08fd9fdbea
>>   Author: Ludovic Courtès <ludo@gnu.org>
>>   Date:   Tue Nov 23 09:06:49 2021 +0100
>>
>>     maint: "make dist" builds tarballs in 'ustar' format.
>>
>> It seems like this actually needs even further updates, as that should
>> allow for a much longer file length in general (although a little
>> difficult to figure out the exact file length allowed).
>>
>> And then the corresponding test suite will need changes as well...
>
> I think independently of the switch to ustar, it’s a good idea for ‘guix
> lint’ to warn about long patch file names, but to warn a bit less
> frequently than today.
>
> In that spirit, your patch is still relevant and worth applying IMO.

Sure, although while I'm mucking around... I went ahead and did some
real-world testing of file lengths usable by ustar.

Using ustar adds a significant buffer, though less than one might think
in the case of guix-VERSION/gnu/packages/patches/*.patch (~151
characters vs. ~99).

I'm guessing this is plenty buffer though, most existing patches were
only a theoretical problem... almost to the point that maybe even
removing the check entirely might be fine.

Updated patch integrating this and the stronger warning suggested by
Philip McGrath.

I haven't yet actually *tested* this updated patch yet, but the previous
iteration tested just fine. :)


live well,
  vagrant

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1.2: 0001-lint-Adjust-patch-file-length-check.patch --]
[-- Type: text/x-diff, Size: 3123 bytes --]

From c0738574a3571977855d655c157ab0ea0f9be6ef Mon Sep 17 00:00:00 2001
From: Vagrant Cascadian <vagrant@debian.org>
Date: Fri, 26 Nov 2021 12:13:45 -0800
Subject: [PATCH] lint: Adjust patch file length check.

With the switch to "ustar" format in commit
bdf5c16ac052af2ca9d5c3acc4acbc08fd9fdbea, the maximum file length has
increased.

* guix/lint.scm (check-patch-file-names): Adjust margin used to check for
  patch file lengths. Increase allowable patch file length appropriate to new
  tar format. Extend warning to explain that long files may break 'make dist'.
* tests/lint.scm: Update tests accordingly.
---
 guix/lint.scm  | 9 ++++++---
 tests/lint.scm | 8 ++++----
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/guix/lint.scm b/guix/lint.scm
index ac2e7b3841..4a5573e86e 100644
--- a/guix/lint.scm
+++ b/guix/lint.scm
@@ -957,8 +957,11 @@ patch could not be found."
 
      ;; Check whether we're reaching tar's maximum file name length.
      (let ((prefix (string-length (%distro-directory)))
-           (margin (string-length "guix-2.0.0rc3-10000-1234567890/"))
-           (max    99))
+           ;; Margin approximating the largest path that "make dist" might
+           ;; create, with a release candidate version, 123456 commits, and
+           ;; git commit hash abcde0.
+           (margin (string-length "guix-92.0.0rc3-123456-abcde0/"))
+           (max    151))
        (filter-map (match-lambda
                      ((? string? patch)
                       (if (> (+ margin (if (string-prefix? (%distro-directory)
@@ -968,7 +971,7 @@ patch could not be found."
                              max)
                           (make-warning
                            package
-                           (G_ "~a: file name is too long")
+                           (G_ "~a: file name is too long which may break 'make dist'")
                            (list (basename patch))
                            #:field 'patch-file-names)
                           #f))
diff --git a/tests/lint.scm b/tests/lint.scm
index 9a91dd5426..8fa0172cf7 100644
--- a/tests/lint.scm
+++ b/tests/lint.scm
@@ -506,17 +506,17 @@
                                  (file-name "x.patch")))))))))
     (check-patch-file-names pkg)))
 
-(test-equal "patches: file name too long"
+(test-equal "patches: file name too long which may break 'make dist'"
   (string-append "x-"
-                 (make-string 100 #\a)
-                 ".patch: file name is too long")
+                 (make-string 152 #\a)
+                 ".patch: file name is too long which may break 'make dist'")
   (single-lint-warning-message
    (let ((pkg (dummy-package
                "x"
                (source
                 (dummy-origin
                  (patches (list (string-append "x-"
-                                               (make-string 100 #\a)
+                                               (make-string 152 #\a)
                                                ".patch"))))))))
      (check-patch-file-names pkg))))
 
-- 
2.30.2


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 227 bytes --]

[bug#51985] lint: Adjust patch file length check.

[Ludovic Courtès]

Hi!

Vagrant Cascadian <vagrant@debian.org> skribis:

> On 2021-11-25, Ludovic Courtès wrote:

[...]

>> I think independently of the switch to ustar, it’s a good idea for ‘guix
>> lint’ to warn about long patch file names, but to warn a bit less
>> frequently than today.
>>
>> In that spirit, your patch is still relevant and worth applying IMO.
>
> Sure, although while I'm mucking around... I went ahead and did some
> real-world testing of file lengths usable by ustar.
>
> Using ustar adds a significant buffer, though less than one might think
> in the case of guix-VERSION/gnu/packages/patches/*.patch (~151
> characters vs. ~99).
>
> I'm guessing this is plenty buffer though, most existing patches were
> only a theoretical problem... almost to the point that maybe even
> removing the check entirely might be fine.

Like I wrote, I think it’s good to have this check even if there were no
hard limits, mostly as a style guideline.

> From c0738574a3571977855d655c157ab0ea0f9be6ef Mon Sep 17 00:00:00 2001
> From: Vagrant Cascadian <vagrant@debian.org>
> Date: Fri, 26 Nov 2021 12:13:45 -0800
> Subject: [PATCH] lint: Adjust patch file length check.
>
> With the switch to "ustar" format in commit
> bdf5c16ac052af2ca9d5c3acc4acbc08fd9fdbea, the maximum file length has
> increased.
>
> * guix/lint.scm (check-patch-file-names): Adjust margin used to check for
>   patch file lengths. Increase allowable patch file length appropriate to new
>   tar format. Extend warning to explain that long files may break 'make dist'.
> * tests/lint.scm: Update tests accordingly.

[...]

> +                           (G_ "~a: file name is too long which may break 'make dist'")

I think you need a comma before “which”, but other than that LGTM!  :-)

Thanks,
Ludo’.

bug#51985: lint: Adjust patch file length check.

[Vagrant Cascadian]

[-- Attachment #1: Type: text/plain, Size: 1392 bytes --]

On 2021-11-28, Ludovic Courtès wrote:
> Vagrant Cascadian <vagrant@debian.org> skribis:
>> On 2021-11-25, Ludovic Courtès wrote:
...
>> From c0738574a3571977855d655c157ab0ea0f9be6ef Mon Sep 17 00:00:00 2001
>> From: Vagrant Cascadian <vagrant@debian.org>
>> Date: Fri, 26 Nov 2021 12:13:45 -0800
>> Subject: [PATCH] lint: Adjust patch file length check.
>>
>> With the switch to "ustar" format in commit
>> bdf5c16ac052af2ca9d5c3acc4acbc08fd9fdbea, the maximum file length has
>> increased.
>>
>> * guix/lint.scm (check-patch-file-names): Adjust margin used to check for
>>   patch file lengths. Increase allowable patch file length appropriate to new
>>   tar format. Extend warning to explain that long files may break 'make dist'.
>> * tests/lint.scm: Update tests accordingly.
>
> [...]
>
>> +                           (G_ "~a: file name is too long which may break 'make dist'")
>
> I think you need a comma before “which”, but other than that LGTM!  :-)

Pushed as 5f547a5c425cc99553ea713703e09a8db9f3c38b with the suggested
comma, and a brief comment explaining what the magic number "151" was
about.

That should bright all the patches into compliance with lint as far as
file length goes, and should work with the ustar format for the "make
dist" produced tarballs.

Don't get too crazy with the extra ~50 characters!

live well,
  vagrant

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 227 bytes --]