Checking for packages with mismatched checksums:
Fix Summary and assign.
Note: fetch works for me.
There is no problem with pkg check -q -s py36-pycparser immediately after installation.
But after python -c 'import pycparser', problems arise.
But python -c 'import pycparser' only updates it once.
Perhaps we only need to run python -c 'import pycparser' once before recording the checksum.
I've noticed the same issue since upgrading to 12.1 (for both the py27 and py37 flavors):
It would be nice to report/resolve this upstream