I know this is a high-volume list so sorry for being yet another voice screaming into your mailbox, but I do not know how else to handle this.
A few months ago, I opened a pull request fixing packed bitfields in ctypes struct/union, which right now are being incorrectly created. The offsets and size are all wrong in some cases, fields which should be packed end up with padding between them.
Since ctypes has no maintainer it has been very hard tracking down someone who is up to review this. So, if this issue sparks some interest to you, or you just want to help me out, please have a look :)
Cheers, Filipe Laíns