$ ./python Lib/test/test_runpy.py
.......................== CPython 3.7.0a0 (heads/master-dirty:39243779f4, Jul 25 2017, 14:32:21) [GCC 6.3.0 20170406]
== Linux-4.10.0-28-generic-i686-athlon-with-debian-stretch-sid little-endian
== hash algorithm: siphash24 32bit
== cwd: /home/serhiy/py/cpython/build/test_python_31873
== CPU count: 2
== encodings: locale=UTF-8, FS=utf-8
Testing with flags: sys.flags(debug=0, inspect=0, interactive=0, optimize=0, dont_write_bytecode=0, no_user_site=0, no_site=0, ignore_environment=0, verbose=0, bytes_warning=0, quiet=0, hash_randomization=1, isolated=0)
Run tests sequentially
0:00:00 load avg: 0.85 [  1/406] test_grammar
0:00:00 load avg: 0.85 [  2/406] test_opcodes
0:00:00 load avg: 0.85 [  3/406] test_dict
0:00:01 load avg: 0.85 [  4/406] test_builtin
0:00:02 load avg: 0.85 [  5/406] test_exceptions
0:00:02 load avg: 0.85 [  6/406] test_types
...

In isolated mode it runs normally.

$ ./python -I Lib/test/test_runpy.py
..............................
----------------------------------------------------------------------
Ran 30 tests in 2.776s

OK