[opam 2.1~alpha] opam remove -a (without arguments) does not work

[kit-ty-kate]

With opam 2.0, using opam remove -a was a useful command which removes any packages that hasn't been purposefully installed by the user.

However with opam 2.1 (master) currently, the following error is given:

$ opam remove -a
The following dependencies couldn't be met:
  - ocaml-variants -> ocaml = 4.11.0 -> ocaml-config
Your request can't be satisfied:
  - Conflicting query for package ocaml-config.1

No solution found, exiting

[AltGr]

From your message, it seems that the dependencies of the base packages are not properly added to the switch roots before the cleanup; obviously trying to remove them then results in a failure.
Thanks for reporting!

[AltGr]

I have a fix for this, but it's stacked on top of other pending PRs.
So you just have to wait to a little more, but it's fixed.