In /usr/bin/diff2patches line 82:
FILES=$(zcat "$diffgz" | lsdiff --strip 1 | egrep -v ^debian/) || \
                                            ^---^ SC2196: egrep is non-standard and deprecated. Use grep -E instead.


In /usr/bin/diff2patches line 86:
	[ ! -z "$file" ] || continue
          ^-- SC2236: Use -n instead of ! -z.


In /usr/bin/diff2patches line 88:
	newFileName="$DEB_PATCHES/$(echo "$file" | sed 's#/#___#g').patch"
                                    ^----------------------------^ SC2001: See if you can use ${variable//search/replace} instead.

For more information:
  https://www.shellcheck.net/wiki/SC2196 -- egrep is non-standard and depreca...
  https://www.shellcheck.net/wiki/SC2001 -- See if you can use ${variable//se...
  https://www.shellcheck.net/wiki/SC2236 -- Use -n instead of ! -z.