On Sun, Oct 30, 2016 at 4:40 AM, James Cowgill <jcowg...@debian.org> wrote: > Control: tags -1 - help > Control: severity -1 important > Control: retitle -1 vlc: should prevent installation on powerpc G3 > > Hi, > > On 30/10/16 00:16, Robert Ou wrote: >> On Sat, Oct 29, 2016 at 3:43 PM, James Cowgill <jcowg...@debian.org> wrote: >>> Control: tags -1 help >>> Control: severity -1 grave >>> >>> Hi, >>> >>> On 29/10/16 23:00, Robert Ou wrote: >>>> Package: src:vlc >>>> Version: 2.2.4-7 >>>> Severity: normal >>>> >>>> Dear Maintainer, >>>> >>>> I decided I wanted to test the performance of Debian PowerPC on my >>>> ancient iMac, and I discovered that vlc will immediately crash with an >>>> illegal instruction right after showing the "Privacy and Network Access >>>> Policy" window and before showing the main window. The crashes look like >>>> the following: >>>> >>>> [ 1560.952016] vlc[997]: unhandled signal 4 at 0ea48f58 nip 0ea48f58 lr >>>> 0ea48f4c code 30001 >>> >>> As powerpc is a release architecture, this bug is RC. >>> >>> I tried running vlc on partch. It managed to get further, but then >>> segfaulted inside QT so it's probably a separate issue. I also had to >>> run it in xvfb so it probably gets different results. >>> >>> Specifically what powerpc hardware do you have? Could you run vlc within >>> gdb to determine which instruction it SIGILLs on (try 'layout asm')? >> >> I was testing on a first-generation iMac with a 333 MHz PowerPC 750 >> (G3). Running vlc under gdb shows that the crash occurs in >> libqt4_plugin.so in QRect::adjusted. The crash occurs on a "lvx >> v0,r10,r5" opcode, which is an Altivec opcode. The G3 however does not >> support Altivec. Here is a backtrace and some more debug information: > > This explains it. From the PowerPC FAQ: > https://wiki.debian.org/PowerPC/FAQ#VLC_crashes_on_startup._What.27s_up_with_that.3F > > " > If VLC immediately crashes, it's probably because you're on a G3 and > VLC was compiled with Altivec instructions. To use VLC on a G3, you > must compile it with the configure option --disable-altivec. > " > > Having said that, I think adding something to vlc's preinst to prevent > installation on systems without altivec would be a good idea here. > > I'm not sure going through all the trouble of compiling vlc twice so it > works on the G3 is worth it here - especially since powerpc may not be > a release architecture in 24 hours... >
Sorry, I completely missed that FAQ entry amongst the other random bugs/quirks listed there. I am totally fine with not having vlc on this system (I didn't expect vlc to actually be able to play anything at a reasonable speed on this ancient a system). However, will blacklisting it in the preinst step break packages like task-xfce-desktop or break people who already had vlc installed and tried to upgrade?
