[Python-modules-team] Bug#989304: lirc FTCBFS: multiple reasons

[Helmut Grohne]

Hi Vagrant,

On Thu, Nov 30, 2023 at 10:43:18AM -0800, Vagrant Cascadian wrote:
> I tried this patch against the current sources, but now it fails at
> dh_auto_configure.
> 
> Build log attached for cross-building i386 (also tried arm64 and armhf
> with the same basic issue).

I think this is all well. The failure you see arises from point 2.
Originally, this was an AC_RUN_IFELSE, which was a hard failure. The
patch changes that to be AC_CHECK_FILE and exporting ac_cv__dev_input
makes configure continue beyond that point.

You may be wondering why this is necessary. The build system wants to
determine whether the host system has /dev/input. Clearly, checking the
existence of that file on the build system is a stupid idea. This
situation is precisely what AC_CHECK_FILE is meant for and it rightly
fails during cross builds, because it has no access to a host system
either.

Then you may wonder whether such a test is reasonable in the first
place. A container may reasonably come without /dev/input. If lirc were
to then disable libinput support, that'd be bad. I agree. Yet, this is
what configure tries to achieve and my patch changes this aspect in a
minimal way (retaining this property). You may be going further and
suggesting to upstream that this check is a bad idea to start with. I
would not disagree. The AC_CHECK_FILE may be an easier sell to upstream.

So if you got this far, I suggest that you just close the bug after
applying most of the patch that made sense and calling it a day.

Thanks for looking into it

Helmut