lib.sh: more verbose error in x_

part of the command was cut off in the output

Signed-off-by: Leah Rowe <info@minifree.org>

include/lib.sh

@@ -103,7 +103,8 @@ expr "X$XBMK_THREADS" : "X-\{0,1\}[0123456789][0123456789]*$" \
     1>/dev/null 2>/dev/null || export XBMK_THREADS=1 # user gave a non-integer
 
 x_() {
-	[ $# -lt 1 ] || $@ || $err "Unhandled non-zero exit: $@"; return 0
+	[ $# -lt 1 ] || $@ || \
+	    $err "Unhandled non-zero exit: $(echo "$@")"; return 0
 }
 
 [ -e ".git" ] || [ -f "version" ] || printf "unknown\n" > version || \