The nice thing is that in our case, the importlib changes are already compatible with the native build. So yes, we can reuse the frozen module from the native build. :-)

Ah, yes. Issue 27641 already prevents that it's cross compiled. This patch was written prior to that and simply rebased.

Still, one problem remains: our strategy for creating importlib.h and importlib_external.h doesn't take out-of-tree builds into account. Even if we regenerate it, frozen.c won't pick it up because its directory is not part of the compiler search path.

Attached is a patch that makes us write the results of _freeze_importlib into $(srcdir)/Python/importlib*.h instead, so that even with an out-of-tree build, we actually update the header files used by frozen.c.