]> Hi, I've come across another issue with Ocamlbuild, and I'm not sure if this one is a bug or a feature. Consider the project tree below; note that everything under lib/ is supposed to produce a foo.cma library, while cmd/ is a command line application that uses foo.cma (and which can be safely ignored for now). |-- _tags |-- lib/ | |-- _tags | |-- foo.mllib | |-- foo_core.mlpack | |-- foo_core/ | | |-- (...) | | | |-- foo_ext.mlpack | |-- foo_ext/ | |-- (...) | |-- cmd/ |-- (...) The file lib/_tags just contains "<foo_core> or <foo_ext>: include". If I issue "ocamlbuild foo.cma" inside the lib/ directory, then foo.cma gets built as expected. However, if I move to the parent directory and issue "ocamlbuild lib/foo.cma", I get an error: ocamlc -pack lib/foo_ext/beta.cmo lib/foo_ext/alpha.cmo -o lib/foo_ext.cmo File "_none_", line 1, characters 0-1: Error: The implementation (obtained by packing) does not match the interface lib/foo_ext.mli: Modules do not match: sig val num : int end is not included in Foo_core.Zero.S Unbound module type Foo_core.Zero.S Command exited with code 2. The problem is of course that "-I lib" should be added to the invocation of ocamlc. For this purpose I've created a myocamlbuild.ml in the root directory, with the following contents: let () = dispatch begin function | After_rules -> Pathname.define_context "lib/foo_ext" ["lib"]; | _ -> () end However, this doesn't work as expected. Perhaps I've misunderstood the purpose of Pathname.define_context? In any case, I would expect a simple example like this one to work even without the need for a myocamlbuild.ml plugin. So, what is missing here? Thanks in advance! Best regards, Dario Teixeira