Re: Test failure when building libarchive-3.1.2

[ludo@gnu.org (Ludovic Courtès)]

Jan Synáček <jan.synacek@gmail.com> skribis:

> On Fri, Nov 20, 2015 at 2:51 PM, Ludovic Courtès <ludo@gnu.org> wrote:
>> Jan Synáček <jan.synacek@gmail.com> skribis:
>>
>>> On Sat, Nov 14, 2015 at 12:40 PM, Ludovic Courtès <ludo@gnu.org> wrote:

[...]

>>>> It would be nice to see if this systematically fails.  If it is
>>>> non-deterministic, we should build it with --keep-failed until it fails
>>>> (removing successful builds with ‘guix gc -d’), collect useful info from
>>>> the build tree, and debug.

[...]

>> I noticed that libarchive uses ‘readdir’ calls as-is, without sorting
>> directory entries afterwards.  Thus, the order of directory entries is
>> effectively non-deterministic and may change depending on the phase of
>> the moon.
>>
>> This has been reported at:
>>
>>   https://github.com/libarchive/libarchive/issues/602
>>
>> Could you add the patch that’s given at that URL to the ‘patches’ field
>> or libarchive’s ‘origin’ form and see if the problem shows up again,
>> preferably building several times in a row?
>
> I built it once and it passed (note that it failed *everytime* I
> wanted to build it).

So this patch appears to solve the issue?

> Maybe a dumb question, but how do I force a rebuild of an already
> built package?:)

You can’t rebuild packages because build processes are assumed to be
deterministic.  However, you can delete a build result with ‘gc -d’, as
mentioned above, and rebuild it afterwards.

HTH,
Ludo’.