The most complex problems were from dealing with switches reverted in
the meantime (gcc5, gmp6, ncurses6).
It's likely that darwin is (still) broken nontrivially.
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.
The runtime paths QT_PLUGIN_PATH, QML_IMPORT_PATH, QML2_IMPORT_PATH, and
XDG_DATA_DIRS did not include the appropriate paths from the current
package being built because addToSearchPath does not add directories
which don't exist.
Try to build e.g. the Qt5 Camera Example[1] and see that qmake fails to
find <GL/gl.h>. This fixes it.
[1] http://doc.qt.io/qt-5/qtmultimediawidgets-camera-example.html
(Although since nixpkgs qtcreator still lacks 'examples', we have to
download the sources manually and use "qmake && make".)
This seems to have been confusing people, using both xlibs and xorg, etc.
- Avoided renaming local (and different) xlibs binding in gcc*.
- Fixed cases where both xorg and xlibs were used.
Hopefully everything still works as before.
Fixes this problem, when building apps in QtCreator:
...(compile output window)
g++ -Wl,-rpath,/nix/store/1w7h7p6s2srfw2ady90k7072991lrnpp-qtbase-5.4.2/lib \
-o qt-test3 main.o mainwindow.o moc_mainwindow.o \
-L/nix/store/1w7h7p6s2srfw2ady90k7072991lrnpp-qtbase-5.4.2/lib \
-lQt5Widgets -lQt5Gui -lQt5Core -lGL -lpthread
/nix/store/b8qhjrwf8sf9ggkjxqqav7f1m6w83bh0-binutils-2.23.1/bin/ld: cannot find -lGL
collect2: error: ld returned 1 exit status
mesa is already in the closure of Qt, so there is no size increase.
The patch is copied into both qt-5.3 and qt-5.4 directories, like other
patches are.
Note that programs still can _run_ against a different libGL (e.g. one
provided by nvidia) by configuring the dynamic linker. For instance,
NixOS sets the LD_LIBRARY_PATH environment variable to
/run/opengl-driver/lib/, meaning that whatever libGL is found there
will be used instead of the default (mesa).
