Known problems¶
Custom ghc version names¶
When installing ghc bindists with custom version names as outlined in
installing custom bindists, then cabal might
be unable to find the correct ghc-pkg (also see #73)
if you use cabal build --with-compiler=ghc-foo. Instead, point it to the full path, such as:
cabal build --with-compiler=$HOME/.ghcup/ghc/<version-name>/bin/ghc or set that GHC version
as the current one via: ghcup set ghc <version-name>.
This problem doesn't exist for regularly installed GHC versions.
Limited distributions supported¶
Currently only GNU/Linux distributions compatible with the upstream GHC binaries are supported.
Precompiled binaries¶
Since this uses precompiled binaries you may run into several problems.
Missing libtinfo (ncurses)¶
You may run into problems with ncurses and missing libtinfo, in case your distribution doesn't use the legacy way of building ncurses and has no compatibility symlinks in place.
Ask your distributor on how to solve this or
try to compile from source via ghcup compile <version>.
Libnuma required¶
This was a bug in the build system of some GHC versions that lead to unconditionally enabled libnuma support. To mitigate this you might have to install the libnuma package of your distribution. See here for a discussion.
Compilation¶
Although this script can compile GHC for you, it's just a very thin wrapper around the build system. It makes no effort in trying to figure out whether you have the correct toolchain and the correct dependencies. Refer to the official docs on how to prepare your environment for building GHC.
Stack support¶
There may be a number of bugs when trying to make ghcup installed GHC versions work with stack, such as:
- https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/188
Further, stack's upgrade procedure may break/confuse ghcup. There are a number of integration issues discussed here:
- https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/153
Windows support¶
Windows support is in early stages. Since windows doesn't support symbolic links properly, ghcup uses a shimgen wrapper. It seems to work well, but there may be unknown issues with that approach.
Windows 7 and Powershell 2.0 aren't well supported at the moment, also see:
- https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/140
- https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/197