Paul,
I’ve seen something similar while I was attempting to build on OS X under makepanda.
It may help to look at this forum post on the makepanda side: https://discourse.panda3d.org/viewtopic.php?t=295&start=30. The basic issue is that interrogate isn’t generalized enough to parse the system header files whilst building the python wrappers; to prevent interrogate from traversing up the tree, you can put stub files in one of the source directories to stop interrogate from finding the system headers.
Best of luck,
Mark