I would like to contribute a test for process sentinels and at the same
time report a bug.  If you execute the test in batch mode with

 emacs -Q -batch -l sentinel-tests.el -f ert-run-tests-batch-and-exit

everything works fine, but in interactive mode

 emacs -Q -l sentinel-tests.el -f ert-run-tests-batch

the sentinel-test-sit-for test fails.

Helmut