Merged requested to merge 3630-nextpart-is-not-compatible-with-set-x-v9_18 into v9_18
If 'set -x' is in effect file.prev gets populated with debugging output. To prevent this open descriptor 3 and redirect stderr from the awk command to descriptor 3. Debugging output will stay directed to stderr.
(cherry picked from commit 10f67938)
Closes #3630 (closed)