dune init exec foo src --lib=lwt.unix fails

[bikallem]

Expected Behavior

dune init exec foo src --lib=lwt.unix to succeed and create a dune file and src folder.

Actual Behavior

Error below.

dune: option `--libs': invalid element in list (`lwt.unix'): invalid
      component name `lwt.unix'
      Library names must be non-empty and composed only of the
      following
      characters: 'A'..'Z', 'a'..'z', '_' or '0'..'9'.
Usage: dune init [OPTION]... INIT_KIND NAME [PATH]
Try `dune init --help' or `dune --help' for more information.

Reproduction

Any lib name with that has characters other than 'A - Z', 'a - z', '_', '0-9'.

dune init exec foo src --lib=lwt.unix

Specifications

• Version of dune (output of dune --version): 2.5.0
• Version of ocaml (output of ocamlc --version): 4.10.0
• Operating system (distribution and version): red hat linux 8.2

[bikallem]

Also it seems the dune exec init accepts both options --lib and --libs. --lib is not documented so shouldn't it fail?? PR #3444 just fixes the first part of the bug. Should we remove --lib from being accepted?

[shonfeder]

@bikallem thanks for reporting this and fixing it! :)

The latter is not a bug in implementation, it's just part of how cmdliner works:

Long names can be specified by any non ambiguous prefix

So dune exec init foo src --li foo will also work! We could add this to the inline documentation somewhere, so we could at least point to that for future bug reports?

[ghost]

Documenting it seems good, but we should make it clear that this is not something we encourage users doing, or at least not in scripts given that it is not future proof.