#!/usr/bin/env bash

EXPR_MSG="evaluating derivation"
PROP_MSG="of derivation"

LOC=$1
if [ -z $1 ]; then
  exec {1}<>"$LOC"
fi

ERROR_LINE=$(<$LOC grep -nF "error:" \
  | tail -n1 \
  | awk '{print substr($1,1,length($1)-1)}' )
<$LOC sed -n "$ERROR_LINE,\$p"

echo "[*] Reason:"
<$LOC grep "evaluating attribute '.*' of derivation" \
  | awk '{ print substr($NF, 2, length($NF)-2), substr($5, 2, length($5)-2)}'