Prelude.head: empty list in GHCi
Summary
Just another evidence that head
is unsafe and brittle, cf. #22185 (closed). I'll send a patch soon.
Steps to reproduce
$ ghci
GHCi, version 9.2.5: https://www.haskell.org/ghc/ :? for help
ghci> :set prompt "%call( )"
ghc-9.2.5: panic! (the 'impossible' happened)
(GHC version 9.2.5:
Prelude.head: empty list
Please report this as a GHC bug: https://www.haskell.org/ghc/reportabug
Expected behavior
I'd expect GHCi to answer
Incorrect %call syntax. Should be %call(a command and arguments).
Environment
- GHC version used: 9.2.5