GHC issueshttps://gitlab.haskell.org/ghc/ghc/-/issues2020-02-25T01:05:27Zhttps://gitlab.haskell.org/ghc/ghc/-/issues/17384:info incorrectly parenthesizes GADT return types in 8.8.12020-02-25T01:05:27ZRyan Scott:info incorrectly parenthesizes GADT return types in 8.8.1Load this code into GHCi 8.8.1:
```hs
{-# LANGUAGE GADTs #-}
{-# LANGUAGE KindSignatures #-}
module Bug where
import Data.Kind
data T :: Type -> Type where
MkT :: T (Maybe Bool)
```
And then run `:info T`. You'll get some unusual r...Load this code into GHCi 8.8.1:
```hs
{-# LANGUAGE GADTs #-}
{-# LANGUAGE KindSignatures #-}
module Bug where
import Data.Kind
data T :: Type -> Type where
MkT :: T (Maybe Bool)
```
And then run `:info T`. You'll get some unusual results:
```
$ /opt/ghc/8.8.1/bin/ghci Bug.hs
GHCi, version 8.8.1: https://www.haskell.org/ghc/ :? for help
Loaded GHCi configuration from /home/rgscott/.ghci
[1 of 1] Compiling Bug ( Bug.hs, interpreted )
Ok, one module loaded.
λ> :info T
type role T nominal
data T a where
MkT :: T Maybe Bool
-- Defined at Bug.hs:7:1
```
Notice how the return type is `T Maybe Bool`, which is wrong. Compare this to GHCi 8.6.5:
```
$ /opt/ghc/8.6.5/bin/ghci Bug.hs
GHCi, version 8.6.5: http://www.haskell.org/ghc/ :? for help
Loaded GHCi configuration from /home/rgscott/.ghci
[1 of 1] Compiling Bug ( Bug.hs, interpreted )
Ok, one module loaded.
λ> :info T
type role T nominal
data T a where
MkT :: T (Maybe Bool)
-- Defined at Bug.hs:7:1
```
This was a regression introduced by someone who shall remain unnamed in 9d9e35574a92773d872efd58a67339a9e054a9f1. Coincidentally, someone who shall remain unnamed will be preparing a fix shortly.8.8.2https://gitlab.haskell.org/ghc/ghc/-/issues/17319Can not load winpthread.dll (ghci)2021-02-26T14:06:16ZIgor HnízdoCan not load winpthread.dll (ghci)## Summary
After a clean install, launching the ghc interpret:
```
C:\WINDOWS\system32>ghci
GHCi, version 8.6.5: http://www.haskell.org/ghc/ :? for help
ghc.exe: Could not load `libwinpthread-1.dll'. Reason: addDLL: libwinpthread-1.dl...## Summary
After a clean install, launching the ghc interpret:
```
C:\WINDOWS\system32>ghci
GHCi, version 8.6.5: http://www.haskell.org/ghc/ :? for help
ghc.exe: Could not load `libwinpthread-1.dll'. Reason: addDLL: libwinpthread-1.dll or dependencies not loaded. (Win32 error 1392)
ghc.exe: panic! (the 'impossible' happened)
(GHC version 8.6.5 for x86_64-unknown-mingw32):
loadArchive "C:\\Program Files\\Haskell Platform\\8.6.5\\mingw\\x86_64-w64-mingw32\\lib\\libpthread.dll.a": failed
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
```
The archive is there.
## Environment
* GHC version used: 8.6.5
Optional:
* Operating System: Windows 10 1903
* System Architecture: 64bit8.8.2