(dirs ...) not recognised in dune2

[houndofsound]

I see the following when offering this line through an ocaml format dune file:

8 | (dirs *)
^^^^
Error: Unknown constructor dirs

it seems to work as expected in a static dune file though.

[bschommer]

I had a similar issue #2711 when adding the (dir ...) in a file included via (include ...).

[ghost]

This is a known limitation. We might be able to loosen this restriction in the future, but not right now. The code is not ready for that.

We could definitely improve the error message though.

[jordwalke]

I have also hit this problem in a different workflow. Just thought I'd mention it.
I needed to copy_files from another library that had this generated dune config:

(include_subdirs unqualified)
(dirs :standard __whitelistThisUnderscoreDir)

But I was unable to copy the files in the underscored directory, because copy_files can't see the directories whitelisted in dirs (since that part of the dune file is generated).

[polytypic]

I also hit this limitation while trying to work around another issue.