Simple update git repo script

update_git_repo() {
    local path="$1"
    local url="$2"
    local build_command="$3"

    if [ -z "$build_command" ]; then
        echo "Attempted to call update_git_repo without build_command specified"
        return
    fi

    local repo_name=$(basename "$url" .git)

    local last_built_commit="$path_build/last_built_commit_$repo_name.txt"
    if [ ! -d "$path" ]; then
        echo "Cloning repo from $url to $path"
        git clone "$url" "$path"

        echo "Building $url"
        pushd "$path" > /dev/null
        chmod +x "$build_command"
        eval "$build_command"
        popd > /dev/null

        git -C "$path" rev-parse HEAD > "$last_built_commit"
        binaries_dirty=true
        echo
        return
    fi

    git -C "$path" fetch
    local latest_commit_hash=$(git -C "$path" rev-parse '@{u}')
    local last_built_hash=""
    [ -f "$last_built_commit" ] && last_built_hash=$(cat "$last_built_commit")

    if [ "$latest_commit_hash" = "$last_built_hash" ]; then
        echo
        return
    fi

    echo "Build out of date for: $path, updating"
    echo 'Pulling...'
    git -C "$path" pull

    echo "Building $url"
    pushd "$path" > /dev/null
    chmod +x "$build_command"
    eval "$build_command"
    popd > /dev/null

    echo "$latest_commit_hash" > "$last_built_commit"
    binaries_dirty=true
    echo
}