unstableUpdater: init

pkgs/common-updater/unstable-updater.nix

@@ -0,0 +1,44 @@
+{ stdenv
+, writeShellScript
+, coreutils
+, git
+, nix
+, common-updater-scripts
+}:
+
+# This is an updater for unstable packages that should always use the latest
+# commit.
+{ url ? null # The git url, if empty it will be set to src.url
+}:
+
+let
+  updateScript = writeShellScript "unstable-update-script.sh" ''
+    set -ex
+
+    url="$1"
+
+    # By default we set url to src.url
+    if [[ -z "$url" ]]; then
+        url="$(${nix}/bin/nix-instantiate $systemArg --eval -E \
+                   "with import ./. {}; $UPDATE_NIX_ATTR_PATH.src.url" \
+            | tr -d '"')"
+    fi
+
+    # Get info about HEAD from a shallow git clone
+    tmpdir="$(${coreutils}/bin/mktemp -d)"
+    ${git}/bin/git clone --bare --depth=1 "$url" "$tmpdir"
+    pushd "$tmpdir"
+    commit_date="$(${git}/bin/git show -s --pretty='format:%cs')"
+    commit_sha="$(${git}/bin/git show -s --pretty='format:%H')"
+    popd
+    ${coreutils}/bin/rm -rf "$tmpdir"
+
+    # update the nix expression
+    ${common-updater-scripts}/bin/update-source-version \
+        "$UPDATE_NIX_ATTR_PATH" \
+        "unstable-$commit_date" \
+        --rev="$commit_sha"
+  '';
+
+in [ updateScript url ]
+

pkgs/top-level/all-packages.nix

@@ -94,6 +94,8 @@ in
 
   genericUpdater = callPackage ../common-updater/generic-updater.nix { };
 
+  unstableGitUpdater = callPackage ../common-updater/unstable-updater.nix { };
+
   nix-update-script = callPackage ../common-updater/nix-update.nix { };
 
   ### Push NixOS tests inside the fixed point