Gotchas of `[TARGETS]`; implicit vs `all` vs combinations about cabal

[philderbeast]

I get an ambiguous target for a package named "all" too;

$ mkdir all

$ cd all

$ cabal init
...

$ cabal build all
Error: [Cabal-7132]
Ambiguous target 'all'. It could be:
    :all (package *)
   all:all (component)

$ cabal test all:tests
Error: [Cabal-7132]
Ambiguous target 'all:tests'. It could be:
    :all:tests (package *:filter)
   pkg:all:tests (package:filter)

[philderbeast]

I also get an ambiguous target if I name a testsuite all.

$ cabal build all
Error: [Cabal-7132]
Ambiguous target 'all'. It could be:
    :all (package *)
   all-component:all (component)