Thank you msg356892 for spear heading this for me. I family things to attend to so I apologize for opening this bug report and then walking away..

As far as recreating this issue. It simple to do. you can either use cython or you can put together a quick script that will make say 150 extensions. put one  line of code in it and compile it.. The results always end up being the same 123 extensions can be loaded on the 124th a TB happens.. It does not matter where the files are inside the package. it is always the 124th one that gets loaded for any one package. importing a pyd from another package does not change the number. The extensions have to be a direct descendant of one single package.