Perhaps if you ran the tests in verbose mode, that could narrow down which test it hangs at. Also, if you can capture a KeyboardInterrupt stack trace, that may help. Not sure if it works with your build setup, but maybe you can run something like

./python -m unittest -v test.test_readline

Not too long ago, I added some tests that run a child process in a pseudoterminal (see the “run_pty” function). There were a few platform specific problems getting that working, so there is a good chance your problem may be related.

I wonder if test hangs when you don’t use “--enable-optimizations”?