src/Casa/Types.hs:52:14: error: Couldn't match expected type ‘Either String ByteString’ with actual type ‘(ByteString, ByteString)’
Summary
trying to install "stack" using cabal with ghc 8.8.1 or 8.10.2 on Darwin x86_64
Steps to reproduce
install ghc-8.10.2 and cabal cabal install stack
Expected behavior
stack would be installed
Environment
- GHC version used: 8.10.2
Optional:
- Operating System: Darwin 10 (at present)
- System Architecture: x86_64
Configuring library for casa-types-0.0.1..
Preprocessing library for casa-types-0.0.1..
Building library for casa-types-0.0.1..
[1 of 2] Compiling Casa.Types ( src/Casa/Types.hs, dist/build/Casa/Types.o, dist/build/Casa/Types.dyn_o )
src/Casa/Types.hs:52:14: error:
• Couldn't match expected type ‘Either String ByteString’
with actual type ‘(ByteString, ByteString)’
• In the pattern: (result, wrong)
In a case alternative:
(result, wrong) | S.null wrong -> pure result
In a stmt of a 'do' block:
case Hex.decode (T.encodeUtf8 bytes) of
(result, wrong) | S.null wrong -> pure result
_ -> fail "Invalid hex key."
|
52 | (result, wrong) | S.null wrong -> pure result
| ^^^^^^^^^^^^^^^