Don't suppress protontricks error messages when getting prefix

step/clean_game_prefix.sh

@@ -85,7 +85,7 @@ if [ -z "$game_prefix" ]; then
 	log_error "no prefix found"
 	"$dialog" \
 		errorbox \
-		"A prefix for the selected game could not be found.\nMake sure you have followed the instructions\non creating a clean prefix"
+		"A prefix for the selected game could not be found.\nMake sure you have followed the instructions on creating a clean prefix.\nCheck the terminal output for more details."
 	exit 1
 fi
 

utils/protontricks.sh

@@ -47,12 +47,22 @@ function apply() {
 }
 
 function get_prefix() {
-	prefix=$( \
-		do_protontricks -c 'echo $WINEPREFIX' "$1" 2>/dev/null || \
-		true \
+	local visible=$(do_protontricks -l | grep -o "$1")
+	if [ -z "$visible" ]; then
+		return 0
+	fi
+
+	local stdout=$( \
+		do_protontricks -c 'echo $WINEPREFIX' "$1" || true \
 	)
-	if [ -d "$prefix" ]; then
-		echo "$prefix"
+
+	if [ -d "$stdout" ]; then
+		echo "$stdout"
+	else
+		log_error \
+			"Protontricks did not find a valid prefix directory. " \
+			"Stdout was:\n$stdout"
+		return 1
 	fi
 }