问题
I am attempting to build my haskell project on NixOS.
Running $ stack build gives the following error.
$ stack build
error: attribute ‘ghc822’ missing, at (string):1:53
(use ‘--show-trace’ to show detailed location information)
What does this error mean and how could I proceed? When I run $ stack build --show-trace as suggested, I get the following output, which I do not understand either.
$ stack build --show-trace
Invalid option `--show-trace'
Usage: stack build [TARGET] [--dry-run] [--pedantic] [--fast]
[--ghc-options OPTIONS] [--flag PACKAGE:[-]FLAG]
([--dependencies-only] | [--only-snapshot] |
[--only-dependencies]) ([--file-watch] | [--file-watch-poll])
[--exec CMD [ARGS]] [--only-configure] [--trace] [--profile]
[--no-strip] [--[no-]library-profiling]
[--[no-]executable-profiling] [--[no-]library-stripping]
[--[no-]executable-stripping] [--[no-]haddock]
[--haddock-arguments HADDOCK_ARGS] [--[no-]open]
[--[no-]haddock-deps] [--[no-]haddock-internal]
[--[no-]haddock-hyperlink-source] [--[no-]copy-bins]
[--[no-]copy-compiler-tool] [--[no-]prefetch]
[--[no-]keep-going] [--[no-]force-dirty] [--[no-]test]
[--[no-]rerun-tests] [--ta|--test-arguments TEST_ARGS]
[--coverage] [--no-run-tests] [--[no-]bench]
[--ba|--benchmark-arguments BENCH_ARGS] [--no-run-benchmarks]
[--[no-]reconfigure] [--[no-]cabal-verbose]
[--[no-]split-objs] [--skip ARG] [--help]
Build the package(s) in this directory/configuration
I tried changing my channel to nixos-17.09 instead of nixos-unstable (and running nix-channel --update), but still get the same error.
Output of $ nix-channel --list is shown below.
$ nix-channel --list
stack https://nixos.org/channels/nixos-17.09
nixos https://nixos.org/channels/nixos-17.09
The output of $ nix-env -qaPA 'nixos.haskell.compiler' shows ghc822 to be found.
$ nix-env -qaPA 'nixos.haskell.compiler'
warning: name collision in input Nix expressions, skipping ‘/home/matthew/.nix-defexpr/channels_root/nixos’
nixos.haskell.compiler.ghc6102Binary ghc-6.10.2-binary
nixos.haskell.compiler.ghc704 ghc-7.0.4
nixos.haskell.compiler.ghc704Binary ghc-7.0.4-binary
nixos.haskell.compiler.ghc7102 ghc-7.10.2
nixos.haskell.compiler.integer-simple.ghc7102 ghc-7.10.2
nixos.haskell.compiler.ghc7103 ghc-7.10.3
nixos.haskell.compiler.integer-simple.ghc7103 ghc-7.10.3
nixos.haskell.compiler.integer-simple.ghc742 ghc-7.4.2
nixos.haskell.compiler.ghc742 ghc-7.4.2
nixos.haskell.compiler.ghc742Binary ghc-7.4.2-binary
nixos.haskell.compiler.ghc763 ghc-7.6.3
nixos.haskell.compiler.ghc783 ghc-7.8.3
nixos.haskell.compiler.integer-simple.ghc783 ghc-7.8.3
nixos.haskell.compiler.ghc784 ghc-7.8.4
nixos.haskell.compiler.integer-simple.ghc784 ghc-7.8.4
nixos.haskell.compiler.ghc801 ghc-8.0.1
nixos.haskell.compiler.integer-simple.ghc801 ghc-8.0.1
nixos.haskell.compiler.ghc802 ghc-8.0.2
nixos.haskell.compiler.integer-simple.ghc802 ghc-8.0.2
nixos.haskell.compiler.integer-simple.ghc821 ghc-8.2.1
nixos.haskell.compiler.ghc821 ghc-8.2.1
nixos.haskell.compiler.integer-simple.ghc822 ghc-8.2.2
nixos.haskell.compiler.ghc822 ghc-8.2.2
nixos.haskell.compiler.integer-simple.ghcHEAD ghc-8.3.20170808
nixos.haskell.compiler.ghcHEAD ghc-8.3.20170808
nixos.haskell.compiler.ghcjs ghcjs-0.2.0
nixos.haskell.compiler.ghcjsHEAD ghcjs-0.2.020170323
nixos.haskell.compiler.jhc jhc-0.8.2
nixos.haskell.compiler.uhc uhc-1.1.9.4
I installed ghc8.2.2 via $ nix-env -iA nixos.haskell.compiler.ghc822, and $ ghc --version now returns
$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 8.2.2
However, I still get the error error: attribute ‘ghc822’ missing, at (string):1:54 when attempting to run $ stack build.
Also, I attempted to see what ghc version my stack is using after this install, and this led to the same attribute ‘ghc822’ missing error.
$ stack ghc -- --version
error: attribute ‘ghc822’ missing, at (string):1:54
(use ‘--show-trace’ to show detailed location information)
回答1:
It seems like your stack wants to retrieve the haskell.packages.ghc822 attribute or perhaps haskell.compiler.ghc822, which is not present in your version of <nixpkgs>.
Please check your channel configuration using sudo nix-channel --list (NixOS) or nix-channel --list. Releases 17.03 and older do not have this attribute. 17.09 and unstable should be fine. To switch your default <nixpkgs> to 17.09, note the name of the channel and run
nix-channel --add https://nixos.org/channels/nixos-17.09 <NAME>
Also run nix-channel --update to make sure you have a recent version. GHC 8.2.2 was added on Oct 31st.
If you don't want to change your channel configuration, I suppose you can set the NIX_PATH environment variable
NIX_PATH=nixpkgs=https://github.com/NixOS/nixpkgs-channels/archive/nixos-unstable.tar.gz stack build
回答2:
Another option is to use a shell.nix. nixos-18.03 comes with ghc 8.2.2, so you can create a shell.nix like:
with import (builtins.fetchGit {
url = https://github.com/NixOS/nixpkgs-channels;
ref = "nixos-18.03";
rev = "cb0e20d6db96fe09a501076c7a2c265359982814";
}) {};
haskell.lib.buildStackProject {
name = "my-project";
buildInputs = [ ghc <otherlibs-here> ];
}
And add the following to your stack.yaml:
nix:
shell-file: shell.nix
Then stack build as usual.
回答3:
You can provide an old GHC version using a shell.nix file place in the root of your project:
with import (fetchTarball https://github.com/NixOS/nixpkgs/archive/83b35508c6491103cd16a796758e07417a28698b.tar.gz) {};
let ghc = haskell.compiler.ghc802;
in haskell.lib.buildStackProject {
inherit ghc;
name = "myEnv";
buildInputs = [ pcre ];
}
Use a tar url from https://github.com/NixOS/nixpkgs/releases for a version of nixpkgs that contains the GHC version you need.
Then run nix-shell in the root of the project. This will put you into a shell in which you can perform stack build successfully since it would have access to the correct GHC version.
回答4:
As palik commented, changing the resolver version -- in my case changing
resolver: lts-11.3
to
resolver: lts-9.1
in stack.yaml is a work-around. I do not know what the deeper issue is but would be interested to know.
回答5:
based on @steve-chávez answer
stack.yaml
resolver: lts-13.19
system-ghc: true
install-ghc: false
nix:
enable: true
path: [nixpkgs=./nix/nixpkgs/default.nix]
shell-file: shell.nix
nix/nixpkgs/default.nix
let
spec = builtins.fromJSON (builtins.readFile ./revision.json);
src = import <nix/fetchurl.nix> {
url = "https://github.com/${spec.owner}/${spec.repo}/archive/${spec.rev}.tar.gz";
inherit (spec) sha256;
};
nixcfg = import <nix/config.nix>;
nixpkgs = builtins.derivation {
system = builtins.currentSystem;
name = "${src.name}-unpacked";
builder = builtins.storePath nixcfg.shell;
inherit src;
args = [
(builtins.toFile "builder" ''
$coreutils/mkdir $out
cd $out
$gzip -d < $src | $tar -x --strip-components=1
'')
];
coreutils = builtins.storePath nixcfg.coreutils;
tar = builtins.storePath nixcfg.tar;
gzip = builtins.storePath nixcfg.gzip;
};
in
import nixpkgs
nix/nixpkgs/update.sh
#!/usr/bin/env nix-shell
#!nix-shell -i bash -p nix curl jq
SCRIPT_DIR=$(dirname "$(readlink -f "$BASH_SOURCE")")
owner="nixos"
repo="nixpkgs-channels"
rev="nixos-unstable"
full_rev=$(curl --silent https://api.github.com/repos/$owner/$repo/git/refs/heads/$rev | jq -r .object.sha)
echo "full_rev=$full_rev"
expected_sha=$(nix-prefetch-url https://github.com/$owner/$repo/archive/$full_rev.tar.gz)
cat >"$SCRIPT_DIR/revision.json" <<EOL
{
"owner": "$owner",
"repo": "$repo",
"rev": "$full_rev",
"sha256": "$expected_sha"
}
EOL
shell.nix
{
#
# there are 2 ways of using stack with nix
# - define custom packages in `stack.yaml` `packages` option (https://docs.haskellstack.org/en/stable/nix_integration/#additions-to-your-stackyaml)
# - define custom package in `shell.nix` AND `shell-file: ...` in `stack.yaml` (https://docs.haskellstack.org/en/stable/nix_integration/#additions-to-your-stackyaml)
#
# we are using second option
ghc # stack expect this file to define a function of exactly one argument that should be called ghc
}:
let
# pkgs = import ./nix/nixpkgs/default.nix {}
pkgs = import <nixpkgs> {};
in
with pkgs;
haskell.lib.buildStackProject {
inherit ghc;
name = "myEnv";
buildInputs = [ cabal-install ];
}
来源：https://stackoverflow.com/questions/47916591/stack-build-error-attribute-ghc822-missing-at-string153