[mythtv-users] gcc 8.3.0 compile 29.1 getting libmythtv-29.so: undefined reference to DVBChannel::Open(DVBChannel*) with --disable-dvb

[Tom Dexter]

On 5/29/19, Tom Dexter <digitalaudiorock at gmail.com> wrote:
> On 5/29/19, Tom Dexter <digitalaudiorock at gmail.com> wrote:
>> I just ran into this today recompiling mythtv on my frontend under
>> Gentoo...apparently others had this before me:
>>
>> https://bugs.gentoo.org/683280
>>
>> The specific error appears to be happening during ld linking
>> mythfrontend:
>>
>> /usr/lib/gcc/i686-pc-linux-gnu/8.3.0/../../../../i686-pc-linux-gnu/bin/ld:
>> ../../libs/libmythtv/libmythtv-29.so: undefined reference to
>> `DVBChannel::Open(DVBChannel*)'
>> collect2: error: ld returned 1 exit status
>>
>> What's especially odd is that I just compiled this exact ebuild a week
>> ago yesterday, the primary difference being that that was gcc 8.2.0
>> and not gcc 8.3.0. I also just verified in the build log that the
>> configure absolutely did specify --disable-dvb. Here's the configure:
>>
>> ./configure  --prefix=/usr --libdir=/usr/lib --libdir-name=lib
>> --mandir=/usr/share/man --enable-audio-alsa --disable-audio-jack
>> --disable-audio-pulseoutput --disable-altivec --disable-dvb
>> --disable-firewire --enable-lirc --enable-libxvid
>> --dvb-path=/usr/include --enable-xrandr --enable-xv --enable-x11
>> --enable-nonfree --disable-libcec --disable-libdns-sd
>> --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libvpx
>> --enable-libass --with-bindings=perl,python --python=python2.7
>> --compile-type=release --disable-stripping --enable-vdpau
>> --disable-vaapi --disable-crystalhd --disable-joystick-menu
>> --enable-symbol-visibility --enable-pic --cpu=pentium4
>> --disable-distcc --disable-ccache --disable-systemd_notify
>> --disable-systemd_journal --disable-mythlogserver
>>
>> As suggested in the bug I'm redoing this with dvb enabled which will
>> pull in the appropriate headers.
>>
>> Any idea why this would suddenly happen when it was fine with gcc 8.2.0?
>>
>> Thanks
>> Tom
>>
> One other detail to note:It appears I actually got that error twice.
> The first one was when trying to link mythavtest apparently, just as
> in the logs posted in the above bug. For some reason in my case, the
> build appears to have continued past that getting the same error
> linking mythfrontend, and exited after that.
>
> Tom
>
Wow...pretty crazy. As I noted in that bug this is clearly happening
specifically with gcc 8.3.0. To get my frontend compiled I added the
dvb USE flag in Gentoo to get it to use --enable-dvb and the build
worked fine. However as a test I revered to gcc-8.2.0 and removed the
dvb USE flag (which uses --disable-dvb) and it worked without a hitch.

That is seriously strange.

Tom