45 lines
1.6 KiB
Nix
45 lines
1.6 KiB
Nix
{stdenv, git}:
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{url, rev ? "HEAD", md5 ? "", sha256 ? ""}:
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/* NOTE:
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fetchgit has one problem: git fetch only works for refs.
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This is because fetching arbitrary (maybe dangling) commits may be a security risk
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and checking whether a commit belongs to a ref is expensive. This may
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change in the future when some caching is added to git (?)
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Usually refs are either tags (refs/tags/*) or branches (refs/heads/*)
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Cloning branches will make the hash check fail when there is an update.
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But not all patches we want can be accessed by tags.
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The workaround is getting the last n commits so that it's likly that they
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still contain the hash we want.
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for now : increase depth iteratively (TODO)
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real fix: ask git folks to add a
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git fetch $HASH contained in $BRANCH
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facility because checking that $HASH is contained in $BRANCH is less
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expensive than fetching --depth $N.
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Even if git folks implemented this feature soon it may take years until
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server admins start using the new version?
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*/
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stdenv.mkDerivation {
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name = "git-export";
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builder = ./builder.sh;
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buildInputs = [git];
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outputHashAlgo = if sha256 == "" then "md5" else "sha256";
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outputHashMode = "recursive";
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outputHash = if sha256 == "" then md5 else sha256;
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inherit url rev;
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impureEnvVars = [
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# We borrow these environment variables from the caller to allow
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# easy proxy configuration. This is impure, but a fixed-output
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# derivation like fetchurl is allowed to do so since its result is
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# by definition pure.
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"http_proxy" "https_proxy" "ftp_proxy" "all_proxy" "no_proxy"
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];
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}
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