goinstall: add -clean flag to docs

Fixes #1629.

R=rsc
CC=golang-dev
https://golang.org/cl/4291057

diff --git a/src/cmd/goinstall/doc.go b/src/cmd/goinstall/doc.go
index 17cc06969295981795510f8b857718b84f03a5a1..15845b574580177cda0d3f02468b7e7294c8db5f 100644 (file)
--- a/src/cmd/goinstall/doc.go
+++ b/src/cmd/goinstall/doc.go
@@ -14,6 +14,7 @@ Usage:
 
 Flags and default settings:
         -a=false          install all previously installed packages
+       -clean=false      clean the package directory before installing
        -dashboard=true   tally public packages on godashboard.appspot.com
        -log=true         log installed packages to $GOROOT/goinstall.log for use by -a
        -u=false          update already-downloaded packages