Some skeletons not building in Pycharm 2018.2

Hi,

Pycharm 2018.2; Windows 10; Python 3.7

Looking at the log file I noticed the warnings below. They're an extract from the log.

Should I ignore these warnings?

2018-07-30 11:18:55,750 [ 631375] INFO - .skeletons.PySkeletonRefresher - Skeleton for _bz2
2018-07-30 11:18:56,032 [ 631657] INFO - .skeletons.PySkeletonRefresher - Skeleton for _bz2_d
2018-07-30 11:18:56,303 [ 631928] INFO - .skeletons.PySkeletonGenerator - Skeleton for _bz2_d failed on J:\Programs\Python\Python37\python.exe. stderr: --
Failed to process '_bz2_d' while nothing yet: dynamic module does not define module export function (PyInit__bz2_d)

2018-07-30 11:19:12,445 [ 648070] INFO - .skeletons.PySkeletonRefresher - Rebuilding skeletons for binaries took 17384 ms
2018-07-30 11:19:12,457 [ 648082] WARN - .skeletons.PySkeletonRefresher - Some skeletons failed to generate
2018-07-30 11:19:12,457 [ 648082] WARN - .skeletons.PySkeletonRefresher - 27 modules failed in 1 interpreter. <a href="#">Details...</a>
2018-07-30 11:19:12,457 [ 648082] WARN - .skeletons.PySkeletonRefresher - Failed modules
2018-07-30 11:19:12,457 [ 648082] WARN - .skeletons.PySkeletonRefresher - _asyncio_d
2018-07-30 11:19:12,457 [ 648082] WARN - .skeletons.PySkeletonRefresher - _bz2_d

Thanks in advance for any help.