bug#49847: OpenGL applications may fail to run on foreign distributions

["Ludovic Courtès" <ludo@gnu.org>]

Hi,

Maxim Cournoyer <maxim.cournoyer@gmail.com> skribis:

> I recently discovered that on systems that used another implementation
> of OpenGL than those provided by Mesa (such as systems using the
> proprietary nvidia or AMD drivers), the OpenGL application would crash,
> sometimes even requiring a reboot of the host system to recover!

Ouch.  Isn’t it similar to the problem with libc’s Name Service Switch
(info "(guix) Application Setup"):

     If the nscd is not running, then [applications] perform the name
  lookup by themselves, by loading the name lookup services into their
  own address space and running it.  These name lookup services—the
  ‘libnss_*.so’ files—are ‘dlopen’’d, but they may come from the host
  system’s C library, rather than from the C library the application is
  linked against (the C library coming from Guix).

     And this is where the problem is: if your application is linked
  against Guix’s C library (say, glibc 2.24) and tries to load NSS plugins
  from another C library (say, ‘libnss_mdns.so’ for glibc 2.22), it will
  likely crash or have its name lookups fail unexpectedly.

That is, Mesa can dlopen “drivers” (shared libs), and if these drivers
come from a foreign distro, the application is likely to crash sooner or
later.

If that’s what happens, we’d have to arrange so that our Mesa doesn’t
dlopen non-Guix shared libs.

Thanks,
Ludo’.