diff -r 54016655b9d7 src/cmd/go/build.go
--- a/src/cmd/go/build.go	Mon Jan 30 11:10:59 2012 -0500
+++ b/src/cmd/go/build.go	Mon Jan 30 18:38:06 2012 +0100
@@ -317,6 +317,10 @@
 		return a
 	}
 
+	if p.Error != nil {
+		fatalf("%s", p.Error)
+	}
+
 	a = &action{p: p, pkgdir: p.t.PkgDir()}
 	if p.pkgdir != "" { // overrides p.t
 		a.pkgdir = p.pkgdir