Bug#917592: libterm-termkey-perl: FTBFS (failing tests)

[Niels Thykier]

gregor herrmann:
> On Sat, 29 Dec 2018 00:25:25 +0000, Santiago Vila wrote:
> 
>> Package: src:libterm-termkey-perl
>> Version: 0.16-3
>> Severity: serious
>> Tags: ftbfs
> 
>> I tried to build this package in buster but it failed:
> 
>> Test Summary Report
>> -------------------
>> t/05flags.t       (Wstat: 11 Tests: 2 Failed: 0)
>>   Non-zero wait status: 11
>>   Parse errors: Bad plan.  You planned 4 tests but ran 2.
> 
> Same in #917497.
> 
> Both tests fail during build and not during autopkgtests (locally and
> on r-b/ci.debian.net).
> 
> After thinking a bit I tried:
> 
> #v+
> --- a/debian/rules
> +++ b/debian/rules
> @@ -4,4 +4,4 @@
>         dh $@
> 
>  override_dh_auto_test:
> -       TERM=vt100 dh_auto_test
> +       TERM=vt100 prove --blib --verbose t/*.t
> #v-
> 
> [...] 
> 
> From the debhelper changelog:
> 
> debhelper (11.5.4) unstable; urgency=medium
> 
>   [ Niels Thykier ]
>   * Dh_Lib.pm: Reopen stdin to read from /dev/null in doit (and its sibling
>     functions) to prevent issues when stdin is open in write-only mode
>     (which is what nohup(1) does).  Thanks to Julian Gilbey for reporting
>     the issue and providing a sample patch for it as well.
>     (Closes: #913663)
> 
> 
> Can this be related? (The failing test operate on \*STDIN.)
> Cc'ing the debhelper bug and debhelper maintainers …
> 
> 
> Cheers,
> gregor
> 
> 

Hi gregor,

Indeed, that could be related.

To confirm it, please consider editing/patching
lib/Debian/Debhelper/Dh_Lib.pm by finding the "_doit" function and
commenting out the following line[1]:

"""
open(STDIN, '<', '/dev/null') or error("redirect STDIN failed: $!");
"""

If your test starts working again after that has been removed, then we
confirmed that is the problem.

Can you elaborate a bit more on what libterm-termkey-perl expects from
STDIN here?  A tty perhaps?  Does/did it work under nohup (without the
debhelper work around to make nohup work)?

Thanks,
~Niels

[1] Introduced in fff0f01c4ceb910ec4d0455718a2f60e22463792 but the
entire commit is not directly revertable.