swarm/api: support mounting manifests via FUSE (#3690)

vendor/bazil.org/fuse/debug.go

@@ -0,0 +1,21 @@
+package fuse
+
+import (
+	"runtime"
+)
+
+func stack() string {
+	buf := make([]byte, 1024)
+	return string(buf[:runtime.Stack(buf, false)])
+}
+
+func nop(msg interface{}) {}
+
+// Debug is called to output debug messages, including protocol
+// traces. The default behavior is to do nothing.
+//
+// The messages have human-friendly string representations and are
+// safe to marshal to JSON.
+//
+// Implementations must not retain msg.
+var Debug func(msg interface{}) = nop