Printing current project file to stdout (#10507) breaks the usual list-bin workflow

[ulysses4ever]

Describe the bug
After #10507 I can't do the usual trick with assigning the output of cabal list-bin to a shell variable.

To Reproduce

This example uses the changelog-d project but can be any package with an executable in it.

❯ set ch (cabal list-bin exe:changelog-d)   # that's fish equivalent for bash `export ch=$(cabal list-bin...)`
Warning: this is a debug build of cabal-install with assertions enabled.

❯ echo $ch
Configuration is affected by the following files: - cabal.project /home/artem/Dev/cabal/changelogs-3.14/changelog-d-fork/dist-newstyle/build/x86_64-linux/ghc-9.6.5/changelog-d-1.0.1/x/changelog-d/build/changelog-d/changelog-d

Notice that the variable now holds not only the path to the executable but also the message about the project file. Needless to say, this worked before #10507.

Expected behavior

The $ch variable only holds the path.

System information

• Operating system: NixOS 24.05
• cabal-head , ghc 9.6.5

---

How to fix

Besides reverting #10507, we could change the output to stderr (notice how Warning: this is a debug build... works fine). I don't know an easy way to do it except swap notice with warn NVM, it's verboseStderr verbosity

cabal/cabal-install/src/Distribution/Client/ProjectPlanning.hs

Line 402 in 287d347

notice verbosity . render . vcat $

This is not morally correct because warn* message are meant for "Non fatal conditions that may be indicative of an error or problem" (according to the docs). But maybe it's okay?