Edit: if I change (in step 6)
-f %{sourceDir}/backend/modules/testcompiled1/qmldir %{buildDir}/backend/modules/testcompiled1
by
-f %{sourceDir}/backend/modules/testcompiled1/qmldir %{buildDir}/backend/testcompiled1
I can now run from QtCreator.
Edit: if I change (in step 6)
-f %{sourceDir} /backend/ modules/ testcompiled1/ qmldir %{buildDir} /backend/ modules/ testcompiled1
by
-f %{sourceDir} /backend/ modules/ testcompiled1/ qmldir %{buildDir} /backend/ testcompiled1
I can now run from QtCreator.