Getting rid of '… does not point to a valid object' for an old git branch

Question

I have a fork of a Git repo and my clone appears to have an issue with an old, no longer existant, branch. I keep seeing this message:

error: refs/heads/t_1140

Answer 1

I run into this error on a regular basis. git remote prune origin does not work for me.

[ Update. AFAIU, I'm running into this problem because of using git alternate. Say I've got repo A, registered as alternate for repo B. When I create a new branch br in repo A, and fetch repo A as remote in repo B, git will create a remote ref .git/refs/remotes/A/br for the new branch. When I delete the branch in repo A, and after the corresponding object is garbage-collected, I get the 'error: refs/remotes/A/br does not point to a valid object!' ]

I've written this script (updated to deal with packed refs) to remove the dangling refs (using the info in Validate if commit exists).

#!/bin/sh

set -e

if [ $# -eq 0 ]; then
    dir="."
else
    dir="$1"
fi

if [ ! -d "$dir" ]; then
    echo "not a dir: $dir"
    exit 1
fi

if [ ! -d "$dir/.git" ]; then
    echo "not a git repo: $dir"
    exit 1
fi

cd "$dir"

files=$(find .git/refs -type f)

for f in $files; do
    id=$(cat "$f")
    if ! git rev-parse --quiet "$id" \
    >/dev/null 2>&1; then
    continue
    fi
    if ! git rev-parse --quiet --verify "$id^{commit}" \
    >/dev/null 2>&1; then
    echo "Removing ref $f with missing commit $id"
    rm "$f"
    fi
done

if [ ! -f .git/packed-refs ]; then
    exit 0
fi

packfiles=$(cat .git/packed-refs \
    | grep -v '#' \
    | awk '{print $2}')

for f in $packfiles; do
    if ! git rev-parse --quiet --verify "$f" \
    >/dev/null 2>&1; then
    continue
    fi
    id=$(git rev-parse "$f")
    if ! git rev-parse --quiet --verify "$id" \
    >/dev/null 2>&1; then
    continue
    fi
    if ! git rev-parse --quiet --verify "$id^{commit}" \
    >/dev/null 2>&1; then
    echo "Removing packed ref $f with missing commit $id"
    git update-ref -d $f
    fi
done