Bug#895215: cypari2 FTBFS with dh-python >= 3.20180313

[Adrian Bunk]

Source: cypari2
Version: 1.1.4-2
Severity: serious

https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/cypari2.html

...
   debian/rules override_dh_auto_test
make[1]: Entering directory '/build/1st/cypari2-1.1.4'
python2 tests/rundoctest.py
Traceback (most recent call last):
  File "tests/rundoctest.py", line 16, in <module>
    import cypari2
  File "/build/1st/cypari2-1.1.4/cypari2/__init__.py", line 1, in <module>
    from .pari_instance import Pari
ImportError: No module named pari_instance
make[1]: *** [debian/rules:16: override_dh_auto_test] Error 1