Here is a reproducer for the first bug.

In Python 3.6:

$ ./python import_bug_1.py
1738
738
Fatal Python error: deallocating None

Current thread 0xb7552700 (most recent call first):
Aborted (core dumped)

In Python 3.5:

$ ./python import_bug_1.py
1709
Traceback (most recent call last):
  File "import_bug_1.py", line 10, in <module>
    from .foo import bar
SystemError: Parent module '' not loaded, cannot perform relative import