test.zsh

#!/usr/bin/env zsh

source TRAPERR.zsh

a() {
    b
}

b() {
    c
}

c() {
    d
}

d() {
    false
}

a

TRAPERR.zsh

#!/usr/bin/env zsh

_err() {
    echo "${fg[red]}$@${reset_color}"
}

# Do not set TRAPERR if we are in an interactive shell
if [[ "$ZSH_ARGZERO" != "-zsh" ]]; then

TRAPERR() {
    # If we are in a $() subshell, do not emit an error message, since
    # it will just get duplicated when the result is an error code
    if [ "$ZSH_SUBSHELL" -gt 0 ]; then
        return
    fi

    # Dump the stack trace
    _err "An error occurred on ${funcfiletrace[1]}"

    local i=1
    for trace in "${(Oa)funcfiletrace[@]}"; do
      local err_file=${trace%%:*}
      local err_line=${trace##*:}
      _err "Frame $i (${err_file}:$err_line)"
      if ! [ -f "$err_file" ]; then
        true
      else
        awk 'NR>L-4 && NR<L+4 { printf "%-5d%4s%s\n",NR,(NR==L?">>> ":""),$0 }' "L=$err_line" "$err_file"
      fi
      echo
      i=$(($i+1))
    done >&2
}

fi