diff --git a/internal/testenv/testenv.go b/internal/testenv/testenv.go
index b036aa6..5cb1327 100644
--- a/internal/testenv/testenv.go
+++ b/internal/testenv/testenv.go
@@ -13,6 +13,7 @@ package testenv
 import (
 	"errors"
 	"flag"
+	"fmt"
 	"internal/cfg"
 	"os"
 	"os/exec"
@@ -32,6 +33,14 @@ func Builder() string {
 	return os.Getenv("GO_BUILDER_NAME")
 }
 
+func MainMust(cond func() bool) {
+	if !cond() {
+		fmt.Println("testenv: warning: can't run any tests")
+		fmt.Println("SKIP")
+		os.Exit(0)
+	}
+}
+
 // HasGoBuild reports whether the current system can build programs with ``go build''
 // and then run them with os.StartProcess or exec.Command.
 func HasGoBuild() bool {