This looks quite fixable.
Rather than patching out MS_LAZYTIME you can probably get away with just defining it in the C part with:
#ifndef MS_LAZYTIME
#define MS_LAZYTIME (1<<25)
#endif
This would be suitable for inclusion in LXD for sure.
The go-md2man is probably best kept as a patch. We’ve run into that problem in other environments too but we’d rather not mangle the code coming from external repositories.
For the net_test.go part, we could add a check to see whether the name can be resolved on the system and skip if it can’t, that would take care of this issue.
If you can confirm that such fixes work for you, then we’d be quite happy to include them.