Failing test on Perl 5.12, incorrectly trying to load Wx/Media.pm

Binary package hint: libwx-perl

In Oneric, libwx-perl is FTBFS due to a failing test at the end of the package build (note that the package compiles fine, this is just a test script). The error message for the failing test is:

Can't locate Wx/Media.pm in @INC (@INC contains: /build/buildd/libwx-perl-0.98/blib/lib /build/buildd/libwx-perl-0.98/blib/arch /etc/perl /usr/local/lib/perl/5.12.3 /usr/local/share/perl/5.12.3 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.12 /usr/share/perl/5.12 /usr/local/lib/site_perl .) at (eval 19) line 1.

This is an upstream bug in the Wx perl module, I am able to duplicate it by directly compiling the upstream tarball in an Oneiric chroot. (And can also confirm that the same tarball compiles just fine in Natty.)

By adding some debug prints where the modules are loaded for that test (in Constant.xs), I've determined that the difference between the Natty and Oneiric builds isn't that Oneiric is failing to install Wx::Media, or installing it incorrectly. The difference is that Natty isn't trying to load it. The load of Wx::Media is conditional on these tests:

#if wxPERL_USE_MEDIA && wxUSE_MEDIACTRL && WXPERL_W_VERSION_GE( 2, 6, 0 )

In Natty this evaluates as false, so Wx::Media is never loaded (and the test passes). In Oneiric, this evaluates as true. The first and third parts of the condition are true in both (wxPERL_USE_MEDIA is defined as '1', and both are using versions of wxwidgets higher than 2.6.0, 2.8.11.0-0ubuntu8 and 2.8.11.0-0ubuntu9). So, that leaves wxUSE_MEDIACTRL as the culprit. A recent change in the wxwidgets2.8 package on Oneiric enabled MediaCtrl where it was previously disabled:

wxwidgets2.8 (2.8.11.0-0ubuntu9) oneiric; urgency=low
  * debian/rules: reenable mediactrl. This allows libwx_gtk2u_media-2.8 to be
    built, as this is required by some applications (LP: #632984)

Further confirmation that this is the cause of the problem: redefining wxUSE_MEDIACTRL to '0' in cpp/setup.h allows libwx-perl to build and pass all tests. This is not an ideal solution (it spews warnings about the redefine), just a hack to prove the source of the problem. A better solution would be to turn MediaCtrl off by default again.