Subject: bug#20255: 'search-paths' should respect both user and system profile.

From: Alex Kost <[email-masked]>
Date: Sat, 21 Nov 2015 21:41:45 +0300

Ludovic Courtès (2015-11-21 11:57 +0300) wrote:

> Alex Kost <[email-masked]> skribis:
>
>> Ludovic Courtès (2015-11-20 01:32 +0300) wrote:
>>
>>> -# Load the system profile's settings.
>>> +if [ -x /run/current-system/profile/bin/guix ]
>>> +then
>>> +  # Crucial variables such as 'MANPATH' or 'INFOPATH' may be missing from the
>>> +  # profiles' individual 'etc/profile'.  Thus, combine both profiles when
>>> +  # computing the search paths.
>>> +  #
>>> +  # This may take a few hundred milliseconds, but it's OK because this is
>>> +  # performed for log-in shells only.
>>> +  eval `/run/current-system/profile/bin/guix package \\
>>> +          -p /run/current-system/profile             \\
>>> +          -p \"$HOME/.guix-profile\" --search-paths`
>>
>> Sorry, but it's not OK for me.  As a user, I'm *strongly* against
>> running 'guix' (or any other program) in /etc/profile.
>
> Why?  (Honest question.)

At first, because of the slowdown: it may be a few hundred milliseconds
for you, but it's several seconds for me.  But actually, even if it was
several milliseconds, I still wouldn't like it, as (IMHO) /etc/profile
should only set variables, and not run external programs.

>> I would really like to have an option to avoid this.  Is it possible?
>
> Not that I know of.  Please read <http://bugs.gnu.org/20255>.

What about making some environment variable which will be honored by
'operating-system-etc-service' procedure.  So depending on this variable
that 'eval ...' command will or will not be added to "/etc/profile"
during 'guix system ...' process.

For example, when I do:

  GUIX_IGNORE_SYSTEM_PROFILE_ENV=1 guix system build my-config.scm

the "etc/profile" of the built system will not contain those 'eval ...'
lines.  WDYT?

-- 
Alex