To reproduce:
1. Comment out the return statement in testEndlessRecursion() function and run debugger.
2. When it stops with a SIGSEGV look at a call stack and expand the last 20th item (...). Wait until it expands (gui freeze may happen).
3. Click "Stop" button and uncomment back the return statement in the same function.
4. Try to build the project now - it complains:

13:12:19: Running steps for project simple...
13:12:19: Configuration unchanged, skipping qmake step.
13:12:19: Could not start process "/usr/bin/make" -j8.
13:12:19: Resource error (fork failure): Cannot allocate memory
Error while building/deploying project simple (kit: Qt 5.15.6 (qt-515-build))
When executing step "Make"
13:12:19: Elapsed time: 00:00.