There are actually two different issues here.

dtrace -q will not work on Fedora-based linux (haven't tried elsewhere) and that probably should be corrected, but that is NOT what causes the test fail. 

The tests' setup checks whether dtrace is usuable, and since it is not, those tests are skipped. 

However, stap IS usable, so those tests run.

test.test_dtrace.SystemTapOptimizedTests.test_line will always fail because it expects files in dtracedata (line.stp and line.stp.expected) that are not there.

I've attached a file showing isolated runs of test_dtrace on a newly built Python 3.8.6 on two Centos 7 systems.

The first is against the official Centos 7 Docker container, and stap fails because Linuxkit kernel modules are not installed. The test_dtrace check for a working stap fails, and all 4 tests are skipped.

The second is against a virtualized Centos 7 where the kernel modules are properly installed and stap works.

I don't see how test_dtrace ever passes on a system with a working /bin/stap command.