package constraints in dune-project does not support not (!)

[hannesm]

Expected Behavior

I want to express the opam constraint: "foo" {with-test & >= "2.0" | ! with-test & >= "1.0"}

I can't since "not" nor "!" are supported.

Actual Behavior

Error: Unknown constructor !

Reproduction

in your dune-project

(package
 (depends
  (ocp-indent
   (or
    (and
     (! :with-test)
     (>= 1.0))
    (and
     :with-test
     (>= 2.0))))