Need help: gir-generated tests fail?

[zaaarf]

I've tried several times, from scratch, but it still seems to fail.

I'm trying to generate the FFI library for libinsane. The result builds, but the tests pretty much all fail. A few examples from the error logs:

tests/layout.c:11:51: error: ‘LibinsaneApi’ undeclared (first use in this function)
   11 |     printf("%s;%zu;%zu\n", "LibinsaneApi", sizeof(LibinsaneApi), alignof(LibinsaneApi));
      |                                                   ^~~~~~~~~~~~
tests/constant.c: In function ‘main’:
tests/layout.c:19:57: error: ‘LibinsaneImgFormat’ undeclared (first use in this function)
   19 |     printf("%s;%zu;%zu\n", "LibinsaneImgFormat", sizeof(LibinsaneImgFormat), alignof(LibinsaneImgFormat));
      |                                                         ^~~~~~~~~~~~~~~~~~
tests/constant.c:32:21: error: ‘guint’ undeclared (first use in this function); did you mean ‘int’?
   32 |     PRINT_CONSTANT((guint) LIBINSANE_CAPABILITY_AUTOMATIC);
      |                     ^~~~~
tests/constant.c:11:22: note: in definition of macro ‘PRINT_CONSTANT’
   11 |     printf(_Generic((CONSTANT_NAME), \
      |                      ^~~~~~~~~~~~~
tests/constant.c:32:21: note: each undeclared identifier is reported only once for each function it appears in
   32 |     PRINT_CONSTANT((guint) LIBINSANE_CAPABILITY_AUTOMATIC);
      |                     ^~~~~
tests/constant.c:11:22: note: in definition of macro ‘PRINT_CONSTANT’
   11 |     printf(_Generic((CONSTANT_NAME), \
      |                      ^~~~~~~~~~~~~
tests/constant.c:32:28: error: expected ‘)’ before ‘LIBINSANE_CAPABILITY_AUTOMATIC’
   32 |     PRINT_CONSTANT((guint) LIBINSANE_CAPABILITY_AUTOMATIC);
      |                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I have built and installed the library succesfully (if ld can find it, why shouldn't gir?). I've had to edit the gir file to fix a couple minor issues, but nothing that should cause this sort of disruption.

Any idea on what could be causing this, or at least on where I could begin looking?

If it helps, I'm attaching my edited gir file. Everything else is pretty much a 1:1 of what the book does.