Configuring Slicer_DEFAULT_HOME_MODULE with "DICOM" fails to bring up Dicom module on startup

[HarryDC]

when implementing set(Slicer_DEFAULT_HOME_MODULE "DICOM") in the toplevel CMAKE file the application fails to enter the DICOM module on startup, conversely if the module is set in DefaultSettings.ini the module correctly comes up.

[HarryDC]

qSlicerModulesMenu::setCurrentModule gets called from the init function of qSlicerSettingsModulesPanel, this seems to be fairly early during the startup, the call with the #define that gets populated from the CMAKE variable, fails and returns a nullptr for an action. But when it's called later with the value that's read from the .ini file i think in qSlicerMainWindow the call succeeds and the dicom module is selected. The second call happens a lot later it looks like it's triggered by postInitializeApplication in qSlicerApplicationHelper