If Slicer and the extension is built in Debug mode then all the Extension tests fail (either using the Experimental or ExperimentalUpload target).

An error popup is displayed for each test:

Debug Error!
Program: ...port/Testing/Cxx/Debug/qSlicerDicomImportModuleCxxTest.exe
Module: 4.7.4
File: global\qglobal.cpp
Line: 2271
ASSERT: "This->isInstalled(slicerHome)?this->IntDir.isEmpty():!this->IntDir.isEmpty()" in file ........\Slicer4\Base\QTCore\qSlicerCoreApplication.cxx, line 331
(Press Retry to debug the application)
[Abort] [Retry] [Ignore]

I've attached to the process with the debugger and found the following problem:

The QString qSlicerUtils::pathWithoutIntDir(const QString& path, const QString& subDirWithoutIntDir, QString& intDir) method is called with these parameters:

Path=”c:/Users/lasso/devel/SlicerRtExtension-win64dbg/DicomRtImport/Testing/Cxx/Debug”
subDirWithoutIntDir=”bin”
intDir=””

As the subDirWithoutIntDir in this case is Cxx instead of bin, the pathWithoutIntDir method returns with intDir="", and therefore the assert is triggered.

When I changed the "bin" string to "Cxx" in the memory before calling pathWithoutIntDir the test was completed successfully.

It would be important to fix this issue, as currently it's almost impossible to run the tests on debug builds (you need to add a delay to the startup of qSlicerDicomRtImportModuleGenericTest to have time for attaching the debugger, then for each run you have to start the test process, quickly attach the debugger, put a breakpoint in pathWithoutIntDir, and overwrite the "bin" constant in memory).