The following GHC versions are defined in haskell.nix (there is a derivation
for each, though not all are cached or tested by CI):
- 9.6.6 (TH is broken in mingwW64, but ucrt64 works)
- 9.8.4
- 9.10.1
- 9.12.1
8.10.7 may still work with older nixpkgs versions, but is broken for nixpkgs-unstable.
The following table shows the Nixpkgs/GHC versions which are built/cached, and which of those are further tested. If you use a combination of Nixpkgs version and GHC version which is in this table, you should hit our cache, saving considering time by not building GHC and a few additional tools.
Note that if you try to use haskell.nix as an overlay over Nixpkgs from a
standard Nixpkgs channel you will likely get a cache miss. To hit our cache you
really should use an instance of Nixpkgs provided by haskell.nix itself.
| Nixpkgs version | Nixpkgs pinning | GHC version | compiler-nix-name |
Tested in CI? |
|---|---|---|---|---|
| unstable | nixpkgs-unstable |
9.6.6 | ghc96 or ghc966 |
Yes |
| unstable | nixpkgs-unstable |
9.8.4 | ghc98 or ghc984 |
Yes |
| unstable | nixpkgs-unstable |
9.10.1 | ghc910 or ghc9101 |
Yes |
| unstable | nixpkgs-unstable |
9.12.2 | ghc912 or ghc9122 |
Yes |
See ci.nix for the source of truth about what is built and tested (in the off chance this document is out-of-sync with your checkout).
See the getting started guide for
instructions on how to set up Nix to take advantage of our cache when building.
This guide also covers where to use the Nixpkgs pinning and compiler-nix-name
settings from the table above. For further information, see the instructions
for how to pin Nixpkgs.
See
overlays/bootstrap.nix
for a full list of all the valid compiler-nix-names beyond what's
cached/tested in CI. You're free to use these, but be ready for longer build
times.
Lastly, see instructions on adding new GHC versions
in the event that what's in haskell.nix doesn't suit your needs.