main-is: inside two-way if/else: Ambiguous values for modulePath field about cabal HOT 6 OPEN

f@x270:/tmp/prova$ cat prova.cabal
cabal-version:   3.0
name:            prova
version:         0.1.0.0
license:         NONE
author:          Francesco Ariis
maintainer:      [email protected]
build-type:      Simple
extra-doc-files: CHANGELOG.md

flag wat

common warnings
    ghc-options: -Wall

executable prova
 import:           warnings
 if flag(wat)
     main-is: bar-foo.hs
 else
     main-is: foo-bar.hs
 build-depends:    base ^>=4.18.1.0
 hs-source-dirs:   app
 default-language: Haskell2010
f@x270:/tmp/prova$ tree app/
app/
├── bar-foo.hs
└── foo-bar.hs

1 directory, 2 files
f@x270:/tmp/prova$ cabal check
Warning: this is a debug build of cabal-install with assertions enabled.
These warnings will likely cause trouble when distributing the package:
Warning: [no-category] No 'category' field.
The following errors will cause portability problems on other environments:
Error: [no-syn-desc] No 'synopsis' or 'description' field.
Error: [license-none] The 'license' field is missing or is NONE.
Error: Hackage would reject this package.
f@x270:/tmp/prova$ cabal build
Warning: this is a debug build of cabal-install with assertions enabled.
Warning: The package list for 'hackage.haskell.org' is 33 days old.
Run 'cabal update' to get the latest list of available packages.
Resolving dependencies...
Build profile: -w ghc-9.6.3 -O1
In order, the following will be built (use -v for more details):
 - prova-0.1.0.0 (exe:prova) (first run)
Warning: this is a debug build of cabal-install with assertions enabled.
Configuring executable 'prova' for prova-0.1.0.0...
Warning: this is a debug build of cabal-install with assertions enabled.
Preprocessing executable 'prova' for prova-0.1.0.0...
Building executable 'prova' for prova-0.1.0.0...
[1 of 1] Compiling Main             ( app/bar-foo.hs, /tmp/prova/dist-newstyle/build/x86_64-linux/ghc-9.6.3/prova-0.1.0.0/x/prova/build/prova/prova-tmp/Main.o )
[2 of 2] Linking /tmp/prova/dist-newstyle/build/x86_64-linux/ghc-9.6.3/prova-0.1.0.0/x/prova/build/prova/prova
f@x270:/tmp/prova$ cabal --version
cabal-install version 3.11.0.0
compiled using version 3.11.0.0 of the Cabal library

/tmp/cabal-9659 (main)$ cabal --version
cabal-install version 3.11.0.0
compiled using version 3.11.0.0 of the Cabal library
/tmp/cabal-9659 (main)$ cabal sdist
Warning: this is a debug build of cabal-install with assertions enabled.
Ambiguous values for modulePath field: '"bar-foo.hs"' and '"foo-bar.hs"'
CallStack (from HasCallStack):
  error, called at src/Distribution/Types/UnqualComponentName.hs:128:7 in Cabal-syntax-3.11.0.0-inplace:Distribution.Types.UnqualComponentName
/tmp/cabal-9659 (main)$ ~/download/cabal --version
cabal-install version 3.10.2.0
compiled using version 3.10.2.1 of the Cabal library
/tmp/cabal-9659 (main)$ ~/download/cabal sdist
Error: cabal: bar-foo.hsfoo-bar.hs doesn't exist