When `act-as-setup configure` fails, it doesn't indicate which
dependencies are missing entirely and which ones don't satisfy the
version constraints. The errors from `cabal build` are more informative,
but aren't available in all contexts (nixpkgs Haskell builds, for
example, use the `act-as-setup` interface). This makes it immediately
clear what sort of dependency error has occurred.

Before (cabal-install 3.12.1.0):

    Configuring test-pkg-0.1.0.0...
    Error: [Cabal-8010]
    Encountered missing or private dependencies:
        base <=4.18,
        foobar,
        test-pkg:{bar-internal, foo-internal}

After:

    Configuring test-pkg-0.1.0.0...
    Error: [Cabal-8010]
    Encountered missing or private dependencies:
        base <=4.18 (installed: 4.19.1.0),
        foobar (missing),
        test-pkg:{bar-internal,foo-internal} (missing: :bar-internal)

From @geekosaur on Matrix:

> since changelog-d uses the cabal file parser to parse changelog files,
> internal braces have to be escaped