bug#41811: `guix search` shows control sequences

bug#41811: `guix search` shows control sequences

[Lars-Dominik Braun]

Hi,

when using `guix search python2-xcffib` on a foreign distribution (Gentoo) not
all control sequences are stripped by the pager (see location and license):

---snip---
name: python2-xcffib
version: 0.6.0
outputs: out
systems: x86_64-linux i686-linux
dependencies: libxcb@1.14 python2-cffi@1.13.2 python2-six@1.14.0
location: 8;;file://xxx/gnu/store/1ccswh99papcvkj028s9myy8kq26y26g-guix-module-union/share/guile/site/3.0/gnu/packages/python-xyz.scmgnu/packages/python-xyz.scm:5437:28;;
homepage: https://github.com/tych0/xcffib
license: 8;;http://directory.fsf.org/wiki/License:ExpatExpat8;;
synopsis: XCB Python bindings
description: Xcffib is a replacement for xpyb, an XCB Python bindings.
It adds support for Python 3 and PyPy.  It is based on cffi.
relevance: 20
---

`guix search python2-xcffib | less` works fine, `unset`ting the environment
variable $LESS or setting it to 'FrX' (i.e. what guix does when it’s missing)
fixes the issue too, so I’m a little puzzled. Some more information:

---snip---
$ env | grep -i less
LESS=-R -M --shift 5
LESSOPEN=|lesspipe %s
PAGER=/usr/bin/less
$ less --version
less 551 (PCRE2 regular expressions)
[…]
$ LANG=C guix describe
Generation 15	Jun 11 2020 17:47:13	(current)
  guix cbd9581
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: cbd9581acc41cd49eb81c2432452cad4de805cbd
---snap---

Cheers,
Lars

bug#41811: `guix search` shows control sequences

[Ludovic Courtès]

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Hi,

Lars-Dominik Braun <lars@6xq.net> skribis:

> $ env | grep -i less
> LESS=-R -M --shift 5
> LESSOPEN=|lesspipe %s
> PAGER=/usr/bin/less
> $ less --version
> less 551 (PCRE2 regular expressions)
> […]

No control sequences if you do “unset LESS” before hand, right?

I think we’ll just override ‘LESS’ unconditionally as shown below.

Thanks,
Ludo’.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: Type: text/x-patch, Size: 750 bytes --]

diff --git a/guix/ui.scm b/guix/ui.scm
index 98b30445c8..2595e44062 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -1563,8 +1563,7 @@ zero means that PACKAGE does not match any of REGEXPS."
       ;; Set 'LESS' so that 'less' exits if everything fits on the screen (F),
       ;; lets ANSI escapes through (r), does not send the termcap
       ;; initialization string (X).
-      (let ((pager (with-environment-variables `(("LESS"
-                                                  ,(or (getenv "LESS") "FrX")))
+      (let ((pager (with-environment-variables `(("LESS" "FrX"))
                      (open-pipe* OPEN_WRITE
                                  (or (getenv "GUIX_PAGER") (getenv "PAGER")
                                      "less")))))

bug#41811: `guix search` shows control sequences

[Lars-Dominik Braun]

Hi,

> No control sequences if you do “unset LESS” before hand, right?
> I think we’ll just override ‘LESS’ unconditionally as shown below.
yes, and the patch fixes the issue.

Thanks,
Lars

bug#41811: `guix search` shows control sequences

[Ludovic Courtès]

Hi,

Lars-Dominik Braun <lars@6xq.net> skribis:

>> No control sequences if you do “unset LESS” before hand, right?
>> I think we’ll just override ‘LESS’ unconditionally as shown below.
> yes, and the patch fixes the issue.

Pushed as e66f243e929bbd94e62e77cfa6a63dfd001ebe07.
Thanks for testing!

Ludo’.