# meant to be sourced. copy/pasted from https://iankelling.org/git/?p=errhandle;a=summary

bash-trace() {
    local -i argc_index=0 arg frame i start=${1:-1} max_indent=8 indent
    local source
    local extdebug=false
    if [[ $(shopt -p extdebug) == *-s* ]]; then
        extdebug=true
    fi

    for ((frame=0; frame < ${#FUNCNAME[@]}-1; frame++)); do
        argc=${BASH_ARGC[frame]}
        argc_index+=$argc
        ((frame < start)) && continue
        if (( ${#BASH_SOURCE[@]} > 1 )); then
            source="${BASH_SOURCE[frame+1]}:${BASH_LINENO[frame]}:"
        fi
        indent=$((frame-start+1))
        indent=$((indent < max_indent ? indent : max_indent))
        printf "%${indent}s↳%sin \`%s" '' "$source" "${FUNCNAME[frame]}"
        if $extdebug; then
            for ((i=argc_index-1; i >= argc_index-argc; i--)); do
                printf " %s" "${BASH_ARGV[i]}"
            done
        fi
        echo \'
    done
}


errcatch() {
    set -E; shopt -s extdebug
    _err-trap() {
        err=$?
        exec >&2
        set +x
        echo "${BASH_SOURCE[1]}:${BASH_LINENO[0]}:in \`$BASH_COMMAND' returned $err"
        bash-trace 2
        set -e
        "${_errcatch_cleanup[@]}"
        echo "$0: exiting with code $err"
        exit $err
    }
    trap _err-trap ERR
    set -o pipefail
}

errcatch