https://raw.githubusercontent.com/omniosorg/omnios-build/master/build/python37/patches/regrtest-processgroup.patch

Running some sub-tests in process groups causes tests to hang - the reason it
not yet known.
Disable the use of process groups for now.

diff -wpruN '--exclude=*.orig' a~/Lib/test/libregrtest/runtest_mp.py a/Lib/test/libregrtest/runtest_mp.py
--- a~/Lib/test/libregrtest/runtest_mp.py	1970-01-01 00:00:00
+++ a/Lib/test/libregrtest/runtest_mp.py	1970-01-01 00:00:00
@@ -32,7 +32,8 @@ assert MAIN_PROCESS_TIMEOUT >= PROGRESS_
 # Time to wait until a worker completes: should be immediate
 JOIN_TIMEOUT = 30.0   # seconds
 
-USE_PROCESS_GROUP = (hasattr(os, "setsid") and hasattr(os, "killpg"))
+USE_PROCESS_GROUP = (hasattr(os, "setsid") and hasattr(os, "killpg")
+	and not sys.platform.startswith("sunos"))
 
 
 def must_stop(result, ns):