gksudo wasn't working because libgksu used wrong sudo file which doesn't have setuid bit
Committer: it isn't optimal, as it won't work on non-NixOS. I've got a
patch for it to use relative paths, but apparently something's wrong
with it and I don't want to kill much more time with it ATM.
Without this, configure will say:
Checking for openal... no
/tmp/nix-build-qtmultimedia-5.5.0.drv-0/qtmultimedia-opensource-src-5.5.0/qtmultimedia.pro:28:
Variable GST_VERSION is not defined.
Checking for resourcepolicy... no
And there may be application runtime errors like
defaultServiceProvider::requestService(): no service found for - "org.qt-project.qt.camera"
After this fix, configure will say:
Checking for openal... no
Checking for gstreamer... yes
Checking for gstreamer_photography... no
Checking for gstreamer_encodingprofiles... yes
Checking for gstreamer_appsrc... yes
Checking for linux_v4l... yes
Checking for resourcepolicy... no
And the above runtime error will not appear.
This fix is similar to 449b6028 ("qt5.multimedia: fix gstreamer
support."), except with Qt 5.5 we also need to set GST_VERSION.
Following a commit by @k0ral, this completes the upgrade of the other
`mediainfo` components.
From the changelog:
```
Version 0.7.79, 2015-11-02
+ CLI/DLL only, XML: new option --Output=MIXML, with XML v2.0beta1
status, not for production, see
https://github.com/MediaArea/MediaAreaXml for more details
+ MediaTrace: support of more than 1 file in XML output.
+ CLI/DLL only, XML: new option --Output=MAXML, with XML v0.1 status, in
order to have bot MediaInfo and MediaTrace in the same output, not for
production, see https://github.com/MediaArea/MediaAreaXml for more
details
x MediaTrace: fixed some invalid outputs
x #B951, Amazon S3 support (REST API v2), CLI/DLL only and if compiled
with libcurl support: URL without credential were badly interpreted
```
The `f_check` script uses `which` to check that the Fortran compiler is
available. `which` is a shell built-in on NixOS, but not on Darwin or
other Linuxes.