Expected Behavior

I expect dune utop to work

Actual Behavior

bigstringaf# dune utop
File "lib/xen/dune", line 5, characters 30-46:
5 | (libraries bigarray-compat mirage-xen-posix)
^^^^^^^^^^^^^^^^
Error: Library "mirage-xen-posix" not found.
Hint: try: dune external-lib-deps --missing .utop/utop.exe

Reproduction

get bigstringaf from https://github.com/inhabitedtype/bigstringaf
run dune utop

the xen (and freestanding) subpackages contain optional parts.

Specifications

• Version of dune (output of dune --version): 2.1.3
• Version of ocaml (output of ocamlc --version) 4.09.0
• Operating system (distribution and version): N/A