{lib, stdenvNoCC, git, git-lfs, cacert}: let urlToName = url: rev: let inherit (lib) removeSuffix splitString last; base = last (splitString ":" (baseNameOf (removeSuffix "/" url))); matched = builtins.match "(.*)\\.git" base; short = builtins.substring 0 7 rev; appendShort = lib.optionalString ((builtins.match "[a-f0-9]*" rev) != null) "-${short}"; in "${if matched == null then base else builtins.head matched}${appendShort}"; in lib.makeOverridable (lib.fetchers.withNormalizedHash { } ( # NOTE Please document parameter additions or changes in # doc/build-helpers/fetchers.chapter.md { url, rev ? "HEAD", leaveDotGit ? deepClone , outputHash ? lib.fakeHash, outputHashAlgo ? null , fetchSubmodules ? true, deepClone ? false , branchName ? null , sparseCheckout ? [] , nonConeMode ? false , name ? urlToName url rev , # Shell code executed after the file has been fetched # successfully. This can do things like check or transform the file. postFetch ? "" , preferLocalBuild ? true , fetchLFS ? false , # Shell code to build a netrc file for BASIC auth netrcPhase ? null , # Impure env vars (https://nixos.org/nix/manual/#sec-advanced-attributes) # needed for netrcPhase netrcImpureEnvVars ? [] , meta ? {} , allowedRequisites ? null }: /* NOTE: fetchgit has one problem: git fetch only works for refs. This is because fetching arbitrary (maybe dangling) commits creates garbage collection risks and checking whether a commit belongs to a ref is expensive. This may change in the future when some caching is added to git (?) Usually refs are either tags (refs/tags/*) or branches (refs/heads/*) Cloning branches will make the hash check fail when there is an update. But not all patches we want can be accessed by tags. The workaround is getting the last n commits so that it's likely that they still contain the hash we want. for now : increase depth iteratively (TODO) real fix: ask git folks to add a git fetch $HASH contained in $BRANCH facility because checking that $HASH is contained in $BRANCH is less expensive than fetching --depth $N. Even if git folks implemented this feature soon it may take years until server admins start using the new version? */ assert deepClone -> leaveDotGit; assert nonConeMode -> (sparseCheckout != []); if builtins.isString sparseCheckout then # Changed to throw on 2023-06-04 throw "Please provide directories/patterns for sparse checkout as a list of strings. Passing a (multi-line) string is not supported any more." else stdenvNoCC.mkDerivation { inherit name; builder = ./builder.sh; fetcher = ./nix-prefetch-git; nativeBuildInputs = [ git cacert ] ++ lib.optionals fetchLFS [ git-lfs ]; inherit outputHash outputHashAlgo; outputHashMode = "recursive"; # git-sparse-checkout(1) says: # > When the --stdin option is provided, the directories or patterns are read # > from standard in as a newline-delimited list instead of from the arguments. sparseCheckout = builtins.concatStringsSep "\n" sparseCheckout; inherit url rev leaveDotGit fetchLFS fetchSubmodules deepClone branchName nonConeMode postFetch; postHook = if netrcPhase == null then null else '' ${netrcPhase} # required that git uses the netrc file mv {,.}netrc export NETRC=$PWD/.netrc export HOME=$PWD ''; impureEnvVars = lib.fetchers.proxyImpureEnvVars ++ netrcImpureEnvVars ++ [ "GIT_PROXY_COMMAND" "NIX_GIT_SSL_CAINFO" "SOCKS_SERVER" ]; inherit preferLocalBuild meta allowedRequisites; passthru = { gitRepoUrl = url; }; } ))