fix(tools/git-r): drop

This has been causing spurious failures in CI and we don't use it, drop
it.

Change-Id: I1608c7178c10274609a50a60473b525d7984cad4
Reviewed-on: https://cl.snix.dev/c/snix/+/30168
Reviewed-by: Ryan Lahfa <masterancpp@gmail.com>
Tested-by: besadii
Autosubmit: Florian Klink <flokli@flokli.de>

tools/depot-deps.nix

@@ -6,7 +6,6 @@ depot.nix.lazy-deps {
   age-keygen.attr = "third_party.nixpkgs.age";
   age.attr = "third_party.nixpkgs.age";
   depotfmt.attr = "tools.depotfmt";
-  git-r.attr = "tools.git-r";
   git-review.attr = "third_party.nixpkgs.git-review";
   gerrit-update.attr = "tools.gerrit-update";
   gerrit.attr = "tools.gerrit-cli";

tools/git-r.nix

@@ -1,138 +0,0 @@
-# Git subcommand loaded into the depot direnv via //tools/depot-deps that can
-# display the r/number for (a) given commit(s) in depot. The r/number is a
-# monotonically increasing number assigned to each commit which correspond to
-# refs/r/* as created by `//ops/pipelines/static-pipeline.yaml`. They can also
-# be used as TVL shortlinks and are supported by //web/atward.
-{ pkgs, lib, ... }:
-
-pkgs.writeTextFile {
-  name = "git-r";
-  destination = "/bin/git-r";
-  executable = true;
-  text = ''
-      set -euo pipefail
-
-      PROG_NAME="$0"
-
-      CANON_BRANCH="canon"
-      CANON_REMOTE="$(git config "branch.$CANON_BRANCH.remote" || echo "origin")"
-      CANON_HEAD="$CANON_REMOTE/$CANON_BRANCH"
-
-      usage() {
-        cat <<EOF
-    Usage: git r [-h | --usage] [<git commit> ...]
-
-      Display the r/number for the given git commit(s). If none is given,
-      HEAD is used as a default. The r/number is a monotonically increasing
-      number assigned to each commit on the $CANON_BRANCH branch in depot
-      equivalent  to the revcount ignoring merged in branches (using
-      git-rev-list(1) internally).
-
-      The r/numbers displayed by \`git r\` correspond to refs created by CI
-      in depot, so they can be used as monotonically increasing commit
-      identifiers that can be used instead of a commit hash. To have
-      \`refs/r/*\` available locally (which is not necessary for the operation
-      of \`git r\`), you may have to enable fetching them like this:
-
-          git config --add remote.origin.fetch '+refs/r/*:refs/r/*'
-
-      They are created the next time you run `git fetch origin`.
-
-    EOF
-        exit "''${1:-0}"
-      }
-
-      eprintf() {
-        printf "$@" 1>&2
-      }
-
-      revs=()
-
-      if [[ $# -le 0 ]]; then
-        revs+=("HEAD")
-      fi
-
-      for arg in "$@"; do
-        # No flags supported at the moment
-        case "$arg" in
-          # --help is mapped to `man git-r` by git(1)
-          # TODO(sterni): git-r man page
-          -h | --usage)
-            usage
-            ;;
-          -*)
-            eprintf 'error: unknown flag %s\n' "$PROG_NAME" "$arg"
-            usage 100 1>&2
-            ;;
-          *)
-            revs+=("$arg")
-            ;;
-        esac
-      done
-
-      for rev in "''${revs[@]}"; do
-        # Make sure $rev is well formed
-        git rev-parse "$rev" -- > /dev/null
-
-        if git merge-base --is-ancestor "$rev" "$CANON_HEAD"; then
-          printf 'r/'
-          git rev-list --count --first-parent "$rev"
-        else
-          eprintf 'error: refusing to calculate r/number: %s is not an ancestor of %s\n' \
-            "$rev" "$CANON_HEAD" 1>&2
-          exit 100
-        fi
-      done
-  '';
-
-  # Test case, assumes that it is executed in a checkout of depot
-  meta.ci.extraSteps.matches-refs = {
-    needsOutput = true;
-    label = "Verify `git r` output matches refs/r/*";
-    command = pkgs.writeShellScript "git-r-matches-refs" ''
-      set -euo pipefail
-
-      export PATH="${lib.makeBinPath [ pkgs.git pkgs.findutils ]}"
-      revs=("origin/canon" "origin/canon~1" "93a746aaaa092ffc3e7eb37e1df30bfd3a28435f")
-
-      failed=false
-
-      # assert_eq DESCRIPTION EXPECTED GIVEN
-      assert_eq() {
-        desc="$1"
-        exp="$2"
-        given="$3"
-
-        if [[ "$exp" != "$given" ]]; then
-          failed=true
-          printf 'error: case "%s" failed\n\texp:\t%s\n\tgot:\t%s\n' "$desc" "$exp" "$given" 1>&2
-        fi
-      }
-
-      git fetch origin '+refs/r/*:refs/r/*'
-
-      for rev in "''${revs[@]}"; do
-        assert_eq \
-          "r/number ref for $rev points at that rev" \
-          "$(git rev-parse "$rev")" \
-          "$(git rev-parse "$(./result/bin/git-r "$rev")")"
-      done
-
-      for rev in "''${revs[@]}"; do
-        assert_eq \
-          "r/number for matches ref pointing at $rev" \
-          "$(git for-each-ref --points-at="$rev" --format="%(refname:short)" 'refs/r/*')" \
-          "$(./result/bin/git-r "$rev")"
-      done
-
-      assert_eq \
-        "Passing multiple revs to git r works as expected" \
-        "$(git rev-parse "''${revs[@]}")" \
-        "$(./result/bin/git-r "''${revs[@]}" | xargs git rev-parse)"
-
-      if $failed; then
-        exit 1
-      fi
-    '';
-  };
-}