# 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'). { ... }: let flake_compat = src: let lockFilePath = src + "/flake.lock"; lockFile = builtins.fromJSON (builtins.readFile lockFilePath); fetchTree = info: if info.type == "github" then { outPath = fetchTarball ({ url = "https://api.${info.host or "github.com"}/repos/${info.owner}/${info.repo}/tarball/${info.rev}"; } // (if info ? narHash then { sha256 = info.narHash; } else { }) ); 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 { }) // (if info ? submodules then { inherit (info) submodules; } 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 = info.path; }; narHash = info.narHash; } else if info.type == "tarball" then { outPath = fetchTarball ({ inherit (info) url; } // (if info ? narHash then { sha256 = info.narHash; } else { }) ); } else if info.type == "gitlab" then { inherit (info) rev narHash lastModified; outPath = fetchTarball ({ url = "https://${info.host or "gitlab.com"}/api/v4/projects/${info.owner}%2F${info.repo}/repository/archive.tar.gz?sha=${info.rev}"; } // (if info ? narHash then { sha256 = info.narHash; } else { }) ); 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 ${toString lockFile.version}"; in result.hydraJobs; prs = builtins.fromJSON ; srcs = builtins.mapAttrs (n: value: builtins.fetchgit { url = "https://github.com/${value.base.repo.owner}/${value.base.repo.name}"; ref = "pulls/${n}/head"; } ) prs; in builtins.mapAttrs (_: flake_compat) srcs