Warn on non-ASCII characters in name:

[ffaf1]

Closes #11197

---

• Patches conform to the coding conventions.
• Any changes that could be relevant to users have been recorded in the changelog.
  • no [ ] Is the change significant? If so, remember to add significance: significant in the changelog file.
• The documentation has been updated, if necessary.
• Manual QA notes have been included.
• Tests have been added. (Ask for help if you don’t know how to write them! Ask for an exemption if tests are too complex for too little coverage!)

Manual QA

cd /tmp/
cabal init foo-α
cd foo-α
cabal check

old cabal will not complain about non-ASCII chars in package name, new cabal will.

[athas]

Is this a full fix? Hackage rejects not only packages with non-ASCII names, but also packages that contain files with non-ASCII names (in my case, it was an extra-source-files file for the test suite).

[ffaf1]

Emh I misread the issue, let me work on it some more.