install_dependencies: don't muck with Qt config for native build

[peat-psuwit]

While the /usr/local/bin trick works for crossbuilding, unfortunately it breaks running tests for native builds. Since it's not needed for native builds anyway, let's skip it there.

[peat-psuwit]

Maybe it's Focal only, but without this CMake projects fails to run QML tests. For example, on the main branch of lomiri-system-settings, with --lxd-image=ubuntu:20.04:

dh_auto_test
        cd obj-x86_64-linux-gnu && make -j17 test ARGS\+=-j17
make[2]: Entering directory '/home/peat/lomiri-system-settings/obj-x86_64-linux-gnu'
Running tests...
/usr/bin/ctest --force-new-ctest-process -j17
Test project /home/peat/lomiri-system-settings/obj-x86_64-linux-gnu
      Start  1: tst-plugins
      Start  2: tst-arguments
      Start  3: tst-systemimage
      Start  4: testmouse
      Start  5: testOtherNetwork
      Start  6: testMainWindow
      Start  7: testLauncherPageComponent
      Start  8: tst-bluetooth
      Start  9: tst-bluetooth-devicemodel
      Start 10: tst-bluetooth-device
      Start 11: tst-wifidbushelper
      Start 12: tst_notifications
 1/12 Test  #2: tst-arguments ....................   Passed    0.02 sec
 2/12 Test  #1: tst-plugins ......................   Passed    0.08 sec
 3/12 Test  #6: testMainWindow ...................***Failed    0.13 sec
qmltestrunner: could not exec '/usr/local/bin/qmltestrunner': No such file or directory

 4/12 Test  #7: testLauncherPageComponent ........***Failed    0.13 sec
qmltestrunner: could not exec '/usr/local/bin/qmltestrunner': No such file or directory

 5/12 Test  #4: testmouse ........................***Failed    0.15 sec
qmltestrunner: could not exec '/usr/local/bin/qmltestrunner': No such file or directory

 6/12 Test #11: tst-wifidbushelper ...............   Passed    0.28 sec
 7/12 Test  #5: testOtherNetwork .................***Failed    2.07 sec
qmltestrunner: could not exec '/usr/local/bin/qmltestrunner': No such file or directory

 8/12 Test  #3: tst-systemimage ..................   Passed    2.31 sec
 9/12 Test  #9: tst-bluetooth-devicemodel ........   Passed    3.03 sec
10/12 Test #12: tst_notifications ................   Passed    3.35 sec
11/12 Test  #8: tst-bluetooth ....................   Passed    9.13 sec
12/12 Test #10: tst-bluetooth-device .............   Passed   13.17 sec

67% tests passed, 4 tests failed out of 12

Total Test time (real) =  13.28 sec

The following tests FAILED:
          4 - testmouse (Failed)
          5 - testOtherNetwork (Failed)
          6 - testMainWindow (Failed)
          7 - testLauncherPageComponent (Failed)
Errors while running CTest

[mardy]

Maybe it's Focal only, but without this CMake projects fails to run QML tests. For example, on the main branch of lomiri-system-settings, with --lxd-image=ubuntu:20.04:

Mmm... I see. It may be that this is a similar issue to what I met before, and for which I added this code: https://github.com/ubports/crossbuilder/blob/master/crossbuilder#L684-L689

Let's merge this; I'll give it a try on xenial, and if it turns out it works, then I'll remove the block I linked above.

[mardy]

Let's merge this; I'll give it a try on xenial, and if it turns out it works, then I'll remove the block I linked above.

Your changes work in xenial too, but the block doing the symlinks seems to be still necessary: I tested the fm-radio-service (which uses cmake) on xenial arm64, and it fails without it. So, let's keep things are they are now.