git.iko.soy/haskell.nix
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haskell.nix/lib/stack-cache-generator.nix
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1# Generate cache entries for dependencies of package defined in `src`
3{ pkgs, haskellLib }:
4{ src
5, stackYaml ? "stack.yaml"
6, sha256map ? null
7 # An alternative to adding `# nix-sha256:` comments into the
8 # stack.yaml file:
9 # sha256map =
10 # { "https://github.com/jgm/pandoc-citeproc"."0.17"
11 # = "0dxx8cp2xndpw3jwiawch2dkrkp15mil7pyx7dvd810pwc22pm2q"; };
12, lookupSha256 ?
13 if sha256map != null
14 then { location, tag, ...}: sha256map."${location}"."${tag}"
15 else _: null
16, resolverSha256 ? null
17, nix-tools ? pkgs.haskell-nix.internal-nix-tools # When building stack projects we use the internal nix-tools (compiled with a fixed GHC version)
18, ...
19}:
20let
21 # We only care about the stackYaml file. If src is a local directory
22 # we want to avoid recalculating the cache unless the stack.yaml file
23 # changes.
25 inherit (haskellLib.fetchResolver {
26 inherit src stackYaml resolverSha256;
27 }) resolver fetchedResolver;
29 # Filter just the stack yaml file and any resolver yaml file it points to.
30 maybeCleanedSource =
31 if haskellLib.canCleanSource src
32 then haskellLib.cleanSourceWith {
33 inherit src;
34 filter = path: type:
35 pkgs.lib.hasSuffix ("/" + stackYaml) path
36 || (resolver != null && pkgs.lib.hasSuffix ("/" + resolver) path);
37 }
38 else src;
40 # All repos served via ssh or git protocols are usually private
41 private = url: pkgs.lib.substring 0 4 url != "http";
43 repos = builtins.fromJSON (builtins.readFile (pkgs.runCommand "stack-repos" {
44 buildInputs = [ nix-tools ];
45 } ''
46 TMP=$(mktemp -d)
47 cd $TMP
48 cp -r "${maybeCleanedSource}/." $TMP
49 chmod -R +w $TMP
50 substituteInPlace ${stackYaml} --replace "# nix-sha256:" "nix-sha256:"
51 ${pkgs.lib.optionalString (fetchedResolver != null) ''
52 substituteInPlace ${stackYaml} --replace "${resolver}" "${fetchedResolver}"
53 ''}
54 stack-repos --stack-yaml ${stackYaml}
55 cp repos.json $out
56 ''));
58 cabalName = path: builtins.readFile (pkgs.runCommand "cabal-name" {
59 buildInputs = [ nix-tools ];
60 } ''
61 cabal-name ${path} > $out
62 '');
64 hashPath = path:
65 builtins.readFile (pkgs.runCommand "hash-path" { preferLocalBuild = true; }
66 "echo -n $(${pkgs.nix}/bin/nix-hash --type sha256 --base32 ${path}) > $out");
67in with pkgs.lib;
68concatMap (dep:
69 let
70 is-private = private dep.url;
71 sha256 = if dep.sha256 != null
72 then dep.sha256
73 else lookupSha256 {
74 location = dep.url;
75 tag = dep.rev;
76 };
77 pkgsrc =
78 if !is-private && sha256 != null
79 then pkgs.fetchgit {
80 inherit (dep) url rev;
81 inherit sha256;
82 }
83 else builtins.fetchGit {
84 inherit (dep) url rev;
85 };
86 in map (subdir: {
87 name = cabalName "${pkgsrc}/${subdir}";
88 inherit (dep) url rev;
89 inherit is-private;
90 sha256 = if !is-private then hashPath pkgsrc else null;
91 } // (optionalAttrs (subdir != "") { inherit subdir; }))
92 (dep.subdirs or [ "" ])) repos