How to display last command that failed when using bash set -e?

Question

I am using set -e to stop execution of a script on first error.

The problem is that this does not tell me what went wrong.

How can update a bash scr

Answer 1

1. make err.sh

   set -e
   trap 'echo "ERROR: $BASH_SOURCE:$LINENO $BASH_COMMAND" >&2' ERR
   

2. include it (. err.sh) in all your scripts.

3. replace any

   ... | while read X ; do ... ; done

   with

   while read X ; do ... ; done < <( ... )

   in your scripts for the trap to give the correct line number/command in the error message