Ctypes error when loading [Vk__Types__Transform_matrix_nv]

[kiblitz]

I don't actually use this module but this issue causes running dune tests to fatally fail (repro with dune test on a dune project that depends on olivine).

Uncaught exception:

  Ctypes_static.Unsupported("struct with no fields")

Raised at Ctypes_structs_computed.seal in file "src/ctypes/ctypes_structs_computed.ml", line 52, characters 30-73
Called from Vk__Types__Transform_matrix_nv in file "lib/Vk__Types__Transform_matrix_nv.ml", line 6, characters 9-26

I think the offending Ctypes line is here.

I'd be surprised if this were specific to my setup, but in any case:

• Fedora release 42 (Adams)
• ocaml-base-compiler = 5.3.0
• dune = 3.20.2

[talex5]

I've had this trying to use dune utop; might be something to do with using byte-code?

(I think the error is genuine, but maybe with native code the linker optimises unused modules out better?)

[kiblitz]

I haven't had much luck with i.e. this stanza:

 (inline_tests
  (modes native))

I think your theory that unused modules are optimized away is certainly reasonable. I don't know enough about dune to understand what's causing the inline_tests binary to link Vk__Types__Transform_matrix_nv.