Import if/ELSE

[eviefp]

Describe the bug
I would like to be able to use else clauses in import-if statements.

Related issue: #5563
Related PR: #5566

To Reproduce
A reasonably short repro is

cabal-version:      2.4
name:               cabal-import-if
version:            0.1.0.0

flag some-flag
  description:
  default: False
  manual: True

common common-1
  build-depends: aeson

common common-2
  build-depends: aeson-lens

executable cabal-import-if
    if flag(some-flag)
      import: common-1
    else
      import: common-1, common-2

    main-is:          Main.hs
    build-depends:    base ^>=4.14.3.0
    hs-source-dirs:   app
    default-language: Haskell2010

Expected behavior
Just having the if works, but adding the else results in a warning and ignoring the imports altogether.

System information

• cabal 3.6.2.0

Additional context
For context, I am trying to work around the no multiple home units limitation. I am doing this because I want to be able to quickly run unit tests while editing both my lib and test units, i.e.:

• reload/recompile fast when I make changes to lib
• reload/recompile fast when I make changes to test
• run unit tests by reloading the test Main file and running it

I was able to accomplish this by:

• adding src to the test stanza's hs-source-dirs
• copy over all build-depends from lib to test (they were transitive dependencies anyway)

The above allows me to run something like

$ ghcid -a -c "cabal repl my-test-stanza -f -O0" --test Main.main

and accomplish all I needed (i.e., fast reloads, run tests).

The problem now becomes, I would like to clean this up:

• I dislike repeating the build-depends
• I would rather have a flag that does the above and the addition to the tests' hs-source-dirs

So the way I tried was:

• create a common stanza with the lib's build-depends
• create a new flag
• use that flag in test

The only problem is, the test stanza already has some common imports, so I can't merge them. I also can't move the if/else to the stanza, because I specifically need it to be always imported in lib but only when flag is set to `test.

[Mikolaj]

OOI, if you add curly braces, does it work? if foo {...} else {...}

[eviefp]

Still get an error on the else branch (so when running with -f-some-flag).

[Mikolaj]

Thanks. Seems like an obvious improvement we'd like to have.