Tweaked things further.

upload-single.sh

@@ -11,7 +11,7 @@ set -x
 cd "$1"
 upload="$(basename "$(pwd)")"
 export CUR_SIZE=$( du -B1 -s . | grep -oE "^[0-9]+" )
-export YEAR=`date +%Y`
+export YEAR=$(date +%Y)
 echo ia upload "archiveteam_archivebot_go_${upload}" * \
 	--sleep=120 \
 	--retries=100 \
@@ -24,6 +24,7 @@ echo ia upload "archiveteam_archivebot_go_${upload}" * \
 	--metadata="creator:Archive Team" \
 	--metadata="date:${YEAR}" \
 	--checksum \
+	--verify \
 	--delete
 
 # TEST SLEEP

uploader.sh

@@ -11,7 +11,18 @@ do
 	echo "Starting new loop..."
 	for pack in */; do
 		echo "Trying claim ${pack}..."
-		flock --verbose -x --nonblock "$pack" /upload-single.sh "$pack" || echo "Could not claim pack!"
+		set +e
+		flock --verbose -x --conflict-exit-code 234 --nonblock "$pack" /upload-single.sh "$pack"
+		lock_rc="${?}"
+		set -e
+		if [ "$lock_rc" -ne 0 ]; then
+			if [ "$lock_rc" -ne 234 ]; then
+				echo "Could not claim pack!"
+			else
+				echo "Error return: ${lock_rc}."
+				exit "${lock_rc}"
+			fi
+		fi
 	done
 	sleep 30
 done