net: comment duplicate constant

Change-Id: If5a4d8eff4e51d72fb9dc1d5db2bfe674ec5753b
Reviewed-on: https://go-review.googlesource.com/c/go/+/176717
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/src/net/tcpsockopt_darwin.go b/src/net/tcpsockopt_darwin.go
index 5b738d23e6d7f9fa7eb75a1df6aadba52dc8065d..da0d173453e0c9331d155f75afbced4932b4ebb4 100644 (file)
--- a/src/net/tcpsockopt_darwin.go
+++ b/src/net/tcpsockopt_darwin.go
@@ -10,6 +10,7 @@ import (
        "time"
 )
 
+// syscall.TCP_KEEPINTVL is missing on some darwin architectures.
 const sysTCP_KEEPINTVL = 0x101
 
 func setKeepAlivePeriod(fd *netFD, d time.Duration) error {