Dune: Set mode-only flags

[inumanag]

Is it possible to pass custom flags for specific modes? For example, dune file below works for dune build main.exe but fails for dune build main.exe.o because ocamlopt does not expect -lfoo. Is there a way to set -lfoo only for exe mode and not for object mode?

Problematic example:

(executable
   (name main)
   (libraries base core ctypes ctypes.foreign ctypes.stubs)
   (link_flags (-cclib -lfoo))
   (modes object exe))

Thanks!

[rgrinberg]

It is not possible, but the feature makes sense. I'll tag as an enhancement in case someone would like to create a proposal for how to support this.

[inumanag]

Thanks.

Is there any (cumbersome) hack around this limitation? I tried adding two executable stanzas but dune was not happy about two stanzas sharing same modules.

[rgrinberg]

You can do what you did and simply copy the module. There's a (copy# ..) action for this purpose.

[nojb]

A cleaner approach depending on your situation may be to define a library with the modules that depend on -lfoo, passing -cclib -lfoo in the library_flags field. Then there should be no need to pass this flag when creating the executable.