Subject: Re: bug#17786: group specified in `build-users-group' does not exist

From: Tomas Cech <[email-masked]>
Date: Tue, 17 Jun 2014 12:04:49 +0200

Hello,

On Tue, Jun 17, 2014 at 11:57:16AM +0200, Ludovic Courtès wrote:
>Hello,
>
>Please keep [email-masked] Cc’d.
>
>Tomas Cech <[email-masked]> skribis:
>
>> On Mon, Jun 16, 2014 at 01:52:36PM +0200, Ludovic Courtès wrote:
>>>Tomas Cech <[email-masked]> skribis:
>>>
>>>> On Mon, Jun 16, 2014 at 09:48:39AM +0200, Ludovic Courtès wrote:
>>>>>Hello,
>>>>>
>>>>>Tomas Cech <[email-masked]> skribis:
>>>>>
>>>>>> guix package: error: build failed: the group `"guix-builders"' specified in
>>>>>> `build-users-group' does not exist
>>>>>>
>>>>>> # grep guix /etc/passwd
>>>>>> guix-builder1:x:61:479:Guix builder 1:/var/empty:/sbin/nologin
>>>>>> guix-builder2:x:62:479:Guix builder 2:/var/empty:/sbin/nologin
>>>>>> guix-builder3:x:63:479:Guix builder 3:/var/empty:/sbin/nologin
>>>>>> guix-builder4:x:64:479:Guix builder 4:/var/empty:/sbin/nologin
>>>>>> guix-builder5:x:65:479:Guix builder 5:/var/empty:/sbin/nologin
>>>>>> # grep guix /etc/group
>>>>>> guix-builders:x:479:guix-builder1,guix-builder2,guix-builder3,guix-builder4,guix-builder5
>>>>>>
>>>>>> Nothing seems to be obviously wrong, but guix ends with this error.
>>>>>
>>>>>Hmm, what does “getent group guix-builders” return?
>>>>>And “getent passwd guix-builder1”?
>>>>
>>>> # getent group guix-builders
>>>> guix-builders:x:479:guix-builder1,guix-builder2,guix-builder3,guix-builder4,guix-builder5
>>>> # getent passwd guix-builder1
>>>> guix-builder1:x:61:479:Guix builder 1:/var/empty:/sbin/nologin
>>>
>>>So that’s all good.
>>>
>>>The daemon simply does that (build.cc):
>>>
>>>--8<---------------cut here---------------start------------->8---
>>>    /* Get the members of the build-users-group. */
>>>    struct group * gr = getgrnam(settings.buildUsersGroup.c_str());
>>>    if (!gr)
>>>        throw Error(format("the group `%1%' specified in `build-users-group' does not exist")
>>>            % settings.buildUsersGroup);
>>>--8<---------------cut here---------------end--------------->8---
>>>
>>>Can you try getgrnam("guix-builders") in C or some other language (from
>>>Guile: (getgrnam "guix-builders")) ?
>>
>> scheme@(guile-user)> (getgrnam "guix-builders")
>> $2 = #("guix-builders" "x" 479 ("guix-builder1" "guix-builder2" "guix-builder3" "guix-builder4" "guix-builder5"))
>
>Then there’s something weird: Guile’s getgrnam directly corresponds to
>libc’s getgrnam(3), which is what guix-daemon uses in the snippet above.
>
>Oh, I see the error message you gave above reads:
>
>  the group `"guix-builders"'
>
>Note the extra double quotes.
>
>Could it be that the script that launches guix-daemon does something
>that amounts to:
>
>  guix-daemon '--build-users-group="guix-builders"'
>
>That is, it leaves the double quotes as is in the argument?

It seems to be that case. Thank you and sorry for the noise...

Best regards,

Tomas