Hello,

I was trying today to split a project in several subdirectories behaving as if they were one (Because of a dependency, we cannot split in one module per subdirectory). So I tried using the (include_subdirs unqualified) stanza.

But then I got lost trying to tell Dune how to compile my lexer and parser (ocamllex and manhir). This is basically the structure that causes the problem:

src
├── dir
│   ├── dune
│   ├── lexer.mll
│   └── parser.mly
├── dune
└── main.ml

where src/dune contains:

(include_subdirs unqualified)

(executable
 (name main)
 (public_name sdkjfbh)
 (flags :standard -w -27-33))

and src/dir/dune contains:

(ocamllex lexer)
(menhir (modules parser))

With that architecture, I get the following error when trying to dune build:

Error: I can't determine what library/executable the files produced by this stanza are part of.

I have tried several things to solve my problem:

• adding a (include_subdirs unqualified) stanza to src/dir/dune, but this hides the modules from src/dir to the others (which is the expected behaviour, but I had to try)

• moving the (menhir ...) stanza to src/dune using a qualified path: (menhir (modules dir/parser)). In that case, I get Error: Unbound module Parser in lexer.mll (when lexer.mll has a dependency in parser.mly, in order to use the token type for instance`).

• moving both the stanzas in src/dune. But then, I get Error: No rule found for lexer.mll and Error: No rule found for parser.mly. If I use a qualified path for the parser, I get rid of the latter but nor the former. And I can't use a qualified path for the lexer without getting Error: dir/lexer.ml does not denote a file in the current directory.

Is there something I didn't try? Is there a way to do this at all? Thank you by advance :-) and I hope I'm not just adding noise