In Python 3.7, typing breaks flake8 with 'type object 'Callable' has no attribute '_abc_registry'

1 job for feature_to_pass_latest_mypy_checks in 1 minute and 13 seconds
Status Job ID Name Coverage
  Build
failed #685
build

00:01:13

 
Name Stage Failure
failed
build Build
make[2]: *** [___dmt_A_mappers_ada_A_mapper.py,cover] Error 1
Makefile.M2M:20: recipe for target '___dmt_A_mappers_ada_A_mapper.py,cover' failed
make[2]: Leaving directory '/builds/taste/dmt/tests-coverage'
make[1]: *** [M2M] Error 2
Makefile:6: recipe for target 'M2M' failed
make[1]: Leaving directory '/builds/taste/dmt/tests-coverage'
Makefile:35: recipe for target 'coverage' failed
make: *** [coverage] Error 1
ERROR: Job failed: exit code 1