Qt5 tests require specific environment

[hadess]

The Qt5 tests were run when compiling the libportal RPM, but the tests don't set up their own environment, which means they're bound to fail when, say, a D-Bus daemon, or a display isn't available.

The tests should be self-standing and be runnable without further configuration from the caller. That would also mean that the tests could be run in the GitHub CI, which they currently aren't.

Test running in koji:

+ cd libportal-0.6
+ /usr/bin/meson test -C redhat-linux-build --num-processes 6 --print-errorlogs
ninja: Entering directory `/builddir/build/BUILD/libportal-0.6/redhat-linux-build'
ninja: no work to do.
1/1 Qt unit test FAIL            0.35s   killed by signal 6 SIGABRT
>>> MALLOC_PERTURB_=130 /builddir/build/BUILD/libportal-0.6/redhat-linux-build/tests/qt5/qt-test
Summary of Failures:
1/1 Qt unit test FAIL            0.35s   killed by signal 6 SIGABRT
Ok:                 0   
Expected Fail:      0   
Fail:               1   
Unexpected Pass:    0   
Skipped:            0   
Timeout:            0   
Full log written to /builddir/build/BUILD/libportal-0.6/redhat-linux-build/meson-logs/testlog.txt

CC @grulja

Full log

[hadess]

This still happens.

$ WAYLAND_DISPLAY=invalid DISPLAY=invalid MALLOC_PERTURB_=241 /home/hadess/Projects/Fedora/merged/libportal/libportal-0.6/redhat-linux-build/tests/qt5/qt-test
qt.qpa.plugin: Could not find the Qt platform plugin "wayland" in ""
qt.qpa.xcb: could not connect to display invalid
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.

Aborted (core dumped)

[smcv]

xvfb-run and dbus-run-session might be helpful here.

[grulja]

This might help: https://src.fedoraproject.org/rpms/qt5-qtbase/blob/rawhide/f/qt5-qtbase.spec#_684