--- /dev/null
+# Compatibility function to allow flakes to be used by
+# non-flake-enabled Nix versions. Given a source tree containing a
+# 'flake.nix' and 'flake.lock' file, it fetches the flake inputs and
+# calls the flake's 'outputs' function. It then returns an attrset
+# containing 'defaultNix' (to be used in 'default.nix'), 'shellNix'
+# (to be used in 'shell.nix').
+
+{ src, system ? builtins.currentSystem or "unknown-system" }:
+
+let
+
+ lockFilePath = src + "/flake.lock";
+
+ lockFile = builtins.fromJSON (builtins.readFile lockFilePath);
+
+ fetchTree =
+ info:
+ if info.type == "github" then
+ { outPath = fetchTarball "https://api.${info.host or "github.com"}/repos/${info.owner}/${info.repo}/tarball/${info.rev}";
+ rev = info.rev;
+ shortRev = builtins.substring 0 7 info.rev;
+ lastModified = info.lastModified;
+ lastModifiedDate = formatSecondsSinceEpoch info.lastModified;
+ narHash = info.narHash;
+ }
+ else if info.type == "git" then
+ { outPath =
+ builtins.fetchGit
+ ({ url = info.url; }
+ // (if info ? rev then { inherit (info) rev; } else {})
+ // (if info ? ref then { inherit (info) ref; } else {})
+ );
+ lastModified = info.lastModified;
+ lastModifiedDate = formatSecondsSinceEpoch info.lastModified;
+ narHash = info.narHash;
+ } // (if info ? rev then {
+ rev = info.rev;
+ shortRev = builtins.substring 0 7 info.rev;
+ } else {
+ })
+ else if info.type == "path" then
+ { outPath = builtins.path { path =
+ if builtins.substring 0 1 info.path == "."
+ then builtins.toString src + "/" + info.path
+ else info.path;
+ };
+ narHash = info.narHash;
+ }
+ else if info.type == "tarball" then
+ { outPath = fetchTarball info.url;
+ narHash = info.narHash;
+ }
+ else if info.type == "gitlab" then
+ { inherit (info) rev narHash lastModified;
+ outPath = fetchTarball "https://${info.host or "gitlab.com"}/api/v4/projects/${info.owner}%2F${info.repo}/repository/archive.tar.gz?sha=${info.rev}";
+ shortRev = builtins.substring 0 7 info.rev;
+ }
+ else
+ # FIXME: add Mercurial, tarball inputs.
+ throw "flake input has unsupported input type '${info.type}'";
+
+ callFlake4 = flakeSrc: locks:
+ let
+ flake = import (flakeSrc + "/flake.nix");
+
+ inputs = builtins.mapAttrs (n: v:
+ if v.flake or true
+ then callFlake4 (fetchTree (v.locked // v.info)) v.inputs
+ else fetchTree (v.locked // v.info)) locks;
+
+ outputs = flakeSrc // (flake.outputs (inputs // {self = outputs;}));
+ in
+ assert flake.edition == 201909;
+ outputs;
+
+ callLocklessFlake = flakeSrc:
+ let
+ flake = import (flakeSrc + "/flake.nix");
+ outputs = flakeSrc // (flake.outputs ({ self = outputs; }));
+ in outputs;
+
+ rootSrc = let
+ # Try to clean the source tree by using fetchGit, if this source
+ # tree is a valid git repository.
+ tryFetchGit = src:
+ if isGit && !isShallow
+ then
+ let res = builtins.fetchGit src;
+ in if res.rev == "0000000000000000000000000000000000000000" then removeAttrs res ["rev" "shortRev"] else res
+ else { outPath = src; };
+ # NB git worktrees have a file for .git, so we don't check the type of .git
+ isGit = builtins.pathExists (src + "/.git");
+ isShallow = builtins.pathExists (src + "/.git/shallow");
+
+ in
+ { lastModified = 0; lastModifiedDate = formatSecondsSinceEpoch 0; }
+ // (if src ? outPath then src else tryFetchGit src);
+
+ # Format number of seconds in the Unix epoch as %Y%m%d%H%M%S.
+ formatSecondsSinceEpoch = t:
+ let
+ rem = x: y: x - x / y * y;
+ days = t / 86400;
+ secondsInDay = rem t 86400;
+ hours = secondsInDay / 3600;
+ minutes = (rem secondsInDay 3600) / 60;
+ seconds = rem t 60;
+
+ # Courtesy of https://stackoverflow.com/a/32158604.
+ z = days + 719468;
+ era = (if z >= 0 then z else z - 146096) / 146097;
+ doe = z - era * 146097;
+ yoe = (doe - doe / 1460 + doe / 36524 - doe / 146096) / 365;
+ y = yoe + era * 400;
+ doy = doe - (365 * yoe + yoe / 4 - yoe / 100);
+ mp = (5 * doy + 2) / 153;
+ d = doy - (153 * mp + 2) / 5 + 1;
+ m = mp + (if mp < 10 then 3 else -9);
+ y' = y + (if m <= 2 then 1 else 0);
+
+ pad = s: if builtins.stringLength s < 2 then "0" + s else s;
+ in "${toString y'}${pad (toString m)}${pad (toString d)}${pad (toString hours)}${pad (toString minutes)}${pad (toString seconds)}";
+
+ allNodes =
+ builtins.mapAttrs
+ (key: node:
+ let
+ sourceInfo =
+ if key == lockFile.root
+ then rootSrc
+ else fetchTree (node.info or {} // removeAttrs node.locked ["dir"]);
+
+ subdir = if key == lockFile.root then "" else node.locked.dir or "";
+
+ flake = import (sourceInfo + (if subdir != "" then "/" else "") + subdir + "/flake.nix");
+
+ inputs = builtins.mapAttrs
+ (inputName: inputSpec: allNodes.${resolveInput inputSpec})
+ (node.inputs or {});
+
+ # Resolve a input spec into a node name. An input spec is
+ # either a node name, or a 'follows' path from the root
+ # node.
+ resolveInput = inputSpec:
+ if builtins.isList inputSpec
+ then getInputByPath lockFile.root inputSpec
+ else inputSpec;
+
+ # Follow an input path (e.g. ["dwarffs" "nixpkgs"]) from the
+ # root node, returning the final node.
+ getInputByPath = nodeName: path:
+ if path == []
+ then nodeName
+ else
+ getInputByPath
+ # Since this could be a 'follows' input, call resolveInput.
+ (resolveInput lockFile.nodes.${nodeName}.inputs.${builtins.head path})
+ (builtins.tail path);
+
+ outputs = flake.outputs (inputs // { self = result; });
+
+ result = outputs // sourceInfo // { inherit inputs; inherit outputs; inherit sourceInfo; };
+ in
+ if node.flake or true then
+ assert builtins.isFunction flake.outputs;
+ result
+ else
+ sourceInfo
+ )
+ lockFile.nodes;
+
+ result =
+ if !(builtins.pathExists lockFilePath)
+ then callLocklessFlake rootSrc
+ else if lockFile.version == 4
+ then callFlake4 rootSrc (lockFile.inputs)
+ else if lockFile.version >= 5 && lockFile.version <= 7
+ then allNodes.${lockFile.root}
+ else throw "lock file '${lockFilePath}' has unsupported version ${toString lockFile.version}";
+
+in
+ rec {
+ defaultNix =
+ result
+ // (if result ? defaultPackage.${system} then { default = result.defaultPackage.${system}; } else {});
+
+ shellNix =
+ defaultNix
+ // (if result ? devShell.${system} then { default = result.devShell.${system}; } else {});
+ }
projects / perso / Immae / Config / Nix.git / blobdiff