cabal sdist target selection is broken

[phadej]

% cabal sdist splitmix
Error: [Cabal-7151]
The component library cannot be packaged for distribution on its own. Only entire packages may be packaged for distribution.

splitmix is the name of package. cabal-install is hallucinating.

[ffaf1]

To reproduce:

cabal init -nm --lib prova
cd prova
cabal sdist prova