.

wcfs/misc.go

@@ -621,7 +621,7 @@ func parseWatchFrame(line string) (stream uint64, msg string, err error) {
 
 	stream, err = strconv.ParseUint(line[:sp], 10, 64)
 	if err != nil {
-		return 0, "", fmt.Errorf("invalid stream")
+		return 0, "", fmt.Errorf("invalid frame: %q (invalid stream)", line)
 	}
 
 	msg = strings.TrimSuffix(line[sp+1:], "\n")

wcfs/wcfs_test.py

@@ -478,7 +478,7 @@ class tWatchLink:
         t._wtx = os.fdopen(wh2, 'wb')
 
         t.rx_eof = chan()   # .rx_eof becomes ready when wcfs closes its tx side
-        t.fatalv = []       # fatal messages go here
+        t.fatalv = []       # fatal messages received from wcfs
 
         # inv.protocol message IO
         t._acceptq  = chan() # (stream, msg)    server originated messages go here
@@ -905,7 +905,7 @@ def test_wcfs():
     )
     if _ == 0:
         raise RuntimeError("%s: did not rx EOF after bad frame " % wl)
-    assert wl.fatalv == []  # XXX
+    assert wl.fatalv == [b'error: invalid frame: "zzz hello\\n" (invalid stream)']
 
     wl.close()
     return