Cannot locate function generated by `ppx_deriving`

[arvidj]

Seems like Merlin cannot “Jump to definition” to functions generated by ppx_deriving.

I created a minimal example where it doesn’t seem to work for me.

If I go here, put my cursor ('m using emacs) on make and do C-c C-l, i.e. merlin-locate, I get the error:

merlin-call-locate: 'make' seems to originate from '_none_' whose ML file could not be found

My merlin-mode version is ;; Package-Version: 20240925.900 which I think is the latest.

[arvidj]

This is not an issue in merlin, but rather in ppx_deriving.create. The latter did not properly populate the loc field of the generated create functions, which explains why merlin couldn't find the definitions. Closing here, see ocaml-ppx/ppx_deriving#297 for a tentative fix in ppx_deriving.create.