Does the build plan include dependencies of sub-libraries that aren't built?

[danidiaz]

Hi, I have a question about how the public sublibraries feature of Cabal works.

Take this repo as an example.

In the repo, the tests in package wumpus-json depend on a public sublibrary ("wumpus-test-support") of wumpus. But the main library of wumpus-json doesn't depend on the sublibrary.

graph TD
    wumpus-json --> wumpus
    wumpus-json-test --> wumpus
    wumpus-json-test --> wumpus-test-support

Loading

If I put an unsatisfiable dependency on the build-depends: of the "wumpus-test-support" sublibrary, and then try to build the main library of "wumpus-json" with cabal build wumpus-json:lib:wumpus-json, I get a build plan error. I thought that perhaps it could still compile, given that the "wumpus-test-support" sublibrary is not required in this case—only for the tests.

Is this the expected behavior?

(I'm using cabal-install 3.6.2.0)

[Mikolaj]

OOI, if you have a single main library and an executable that does not use it, does cabal build the main library when you ask it specifically to run the executable?

[danidiaz]

if you have a single main library and an executable that does not use it, does cabal build the main library when you ask it specifically to run the executable?

No, it doesn't build the library.

However, if I put an unsatisfiable dependency on the build-depends: of the library and try to build the executable, the build fails.

Perhaps related to per-component dependency solving? #4087?

[fgaz]

Perhaps related to per-component dependency solving? #4087?

Yes, that's exactly it. Closing in favor of #4087.

I wonder what's the state of that ticket