`cabal install` prints unhelpful error when .cabal filename does not match the package name

[falsifian]

Describe the bug

In a project where the .cabal file has underscores in the name, cabal install fails with an unhelpful error message:

dieVerbatim: user error (cabal: Package .cabal file not found in the tarball:
/tmp/cabal-install.-42328/dist-newstyle/tmp/src-42328/note-graph-0.0.0.0/note-graph.cabal
)

After much head-scratching, I realized the problem was I needed to rename note_graph.cabal to note-graph.cabal.

To Reproduce Steps to reproduce the behavior:

• Put the following in a file called a_b.cabal.

  
  cabal-version: 2.2
  name: a-b
  version: 0.0.0.0
  build-type: Simple

executable x default-language: Haskell2010 build-depends: base main-is: Main.hs

* Put something in `Main.hs`.
* `cabal v2-install .:x`

**Expected behavior**

One of the following would be preferrable:
* The installation works.
* Cabal prints an error like `Your .cabal file should not have underscores in the name.`

**System information**
 OpenBSD current

I've got custom-built `ghc` and `cabal-install` ports; let me know if you'd like me to retry with an unmodified install.

```falsifian moth d $ ghc --version
The Glorious Glasgow Haskell Compilation System, version 8.6.4
falsifian moth d $ cabal --version
cabal-install version 3.4.0.0
compiled using version 3.4.0.0 of the Cabal library```

[jneira]

@falsifian thanks for reporting the error which i can reproduce with last cabal-3.4.0.0 Points to consider:

• cabal v2-build lets you build packages which .cabal file name differs from the package name described in that file (it is any difference ,not only between - and _)
• but cabal install generates a package.tar distribution file and then uses it to install the package like it would downloaded it from hackage. This install from a tar file needs that the .cabal file name matches exactly the package name, so it fails
• that means the package will not be able to be uploaded to hackage as cabal check tell us:

PS D:\dev\ws\haskell\cabal-test> cabal check
Warning: The filename .\cabal_test.cabal does not match package name
(expected: cabal-test.cabal)
Warning: Hackage would reject this package.

So we could do:

• Convert the warning in cabal check in an error for cabal install and cabal build
• Fix cabal install to match the behaviour of cabal build and not throw an error only for local tars generated by cabal install itself, i guess it will be tricky
• Throw an error in cabal install using the same code cabal check uses to print the warning

Imo the build and install behaviour should be coherent and throw an error, but if it is already a warning is cause someone would be using .cabal names different from package names locally (???). So i would vote for 2, although 3 will be easier to implement i guess

[falsifian]

@jneira Thanks for the analysis. I don't have strong opinions or intimate knowledge of cabal, so I'll leave the discussion to others here and in #6299. I've learned the lesson already, so it's not a problem for me unless I forget :)

[jneira]

As a easier to do improvement, we could improve the actual error message, without touching actual semantics