runghc should give an error when the path to ghc is invalid
runghc has a -f option which allows to specify the path to GHC. However, it uses rawSystem and if the path is incorrect, we only get a nonzero exit code. For example, attempting to use "ghc -fdefer-type-errors X.hs" gives absolutely no output.
Attached patch uses findExecutable and gives an error message if the executable is not found. This is not the ideal solution, but I think it's better than the current state.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 7.6.3 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | None |
| Test case | |
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