2015/tricks: fix build

Change-Id: I636b88872fa9e65a7e4d32cf22f44e559d156a43
Reviewed-on: https://go-review.googlesource.com/13776
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
diff --git a/2015/tricks/anon-interface.go b/2015/tricks/anon-interface.go
index 676fd71..71c0c02 100644
--- a/2015/tricks/anon-interface.go
+++ b/2015/tricks/anon-interface.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import (
diff --git a/2015/tricks/compare-map.go b/2015/tricks/compare-map.go
index e95e133..6d5e112 100644
--- a/2015/tricks/compare-map.go
+++ b/2015/tricks/compare-map.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import "io/ioutil"
diff --git a/2015/tricks/compare.go b/2015/tricks/compare.go
index 8a9162a..89ca5d3 100644
--- a/2015/tricks/compare.go
+++ b/2015/tricks/compare.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import "fmt"
diff --git a/2015/tricks/compare2.go b/2015/tricks/compare2.go
index 6687f34..0271f90 100644
--- a/2015/tricks/compare2.go
+++ b/2015/tricks/compare2.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import "fmt"
diff --git a/2015/tricks/cons.go b/2015/tricks/cons.go
index 6a79e0a..c69535c 100644
--- a/2015/tricks/cons.go
+++ b/2015/tricks/cons.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import "fmt"
diff --git a/2015/tricks/embed.go b/2015/tricks/embed.go
index a987d69..0eb7e9c 100644
--- a/2015/tricks/embed.go
+++ b/2015/tricks/embed.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import "fmt"
diff --git a/2015/tricks/json-decode.go b/2015/tricks/json-decode.go
index 4cb20e5..313561e 100644
--- a/2015/tricks/json-decode.go
+++ b/2015/tricks/json-decode.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import (
diff --git a/2015/tricks/json-encode.go b/2015/tricks/json-encode.go
index 106c5a9..a7aab97 100644
--- a/2015/tricks/json-encode.go
+++ b/2015/tricks/json-encode.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import (
diff --git a/2015/tricks/json-nest.go b/2015/tricks/json-nest.go
index 90c68df..8063ae1 100644
--- a/2015/tricks/json-nest.go
+++ b/2015/tricks/json-nest.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import (
diff --git a/2015/tricks/method-http.go b/2015/tricks/method-http.go
index eeb7f26..ad20864 100644
--- a/2015/tricks/method-http.go
+++ b/2015/tricks/method-http.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import "net/http"
diff --git a/2015/tricks/method-once.go b/2015/tricks/method-once.go
index 186296d..7c2c12f 100644
--- a/2015/tricks/method-once.go
+++ b/2015/tricks/method-once.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import "sync"
diff --git a/2015/tricks/method-values-1.go b/2015/tricks/method-values-1.go
index 99044f1..c1a8ab1 100644
--- a/2015/tricks/method-values-1.go
+++ b/2015/tricks/method-values-1.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import (
diff --git a/2015/tricks/method-values-2.go b/2015/tricks/method-values-2.go
index 14c41a5..5ee0b41 100644
--- a/2015/tricks/method-values-2.go
+++ b/2015/tricks/method-values-2.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import (
diff --git a/2015/tricks/repeated.go b/2015/tricks/repeated.go
index 3b86e97..88fec40 100644
--- a/2015/tricks/repeated.go
+++ b/2015/tricks/repeated.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 // BEGIN OMIT
diff --git a/2015/tricks/repeated2.go b/2015/tricks/repeated2.go
index 4d11e40..164158f 100644
--- a/2015/tricks/repeated2.go
+++ b/2015/tricks/repeated2.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 // BEGIN1 OMIT
diff --git a/2015/tricks/string_test.go b/2015/tricks/string_test.go
index 76a739f..d626c1d 100644
--- a/2015/tricks/string_test.go
+++ b/2015/tricks/string_test.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package strings_test
 
 import (
diff --git a/2015/tricks/string_test2.go b/2015/tricks/string_test2.go
index 3afb4e9..ed692a2 100644
--- a/2015/tricks/string_test2.go
+++ b/2015/tricks/string_test2.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package strings_test
 
 import (
diff --git a/2015/tricks/template.go b/2015/tricks/template.go
index e6b79fe..f333a75 100644
--- a/2015/tricks/template.go
+++ b/2015/tricks/template.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import (