Solver failed:
Ocamlbuild knows of no rules that apply to a target named Jsonm.odoc. This can happen if you ask Ocamlbuild to build a target with the wrong extension (e.g. .opt instead of .native) or if the source files live in directories that have not been specified as include directories.
Backtrace:
- Failed to build the target doc/api.docdir/index.html