GHC incorrectly suggests a data constructor is in scope in 8.2
After commit 343cb32d (the fix for #13568 (closed)), which debuted in GHC 8.2, GHC thinks that out-of-scope identifiers are actually in-scope!
module Bug where
f :: T
f = undefined
In GHC 8.2.1-rc3, the error message is:
$ /opt/ghc/8.2.1/bin/ghc Bug.hs
[1 of 1] Compiling Bug ( Bug.hs, Bug.o )
Bug.hs:3:6: error:
Not in scope: type constructor or class ‘T’
A data constructor of that name is in scope; did you mean DataKinds?
|
3 | f :: T
| ^
Compare this to GHC 8.0.2, which gives a more sensible error message:
$ /opt/ghc/8.0.2/bin/ghc Bug.hs
[1 of 1] Compiling Bug ( Bug.hs, Bug.o )
Bug.hs:3:6: error: Not in scope: type constructor or class ‘T’
Trac metadata
Trac field | Value |
---|---|
Version | 8.2.1-rc2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | mrkgnao |
Operating system | |
Architecture |