5 files changed, 20 insertions, 1 deletions
diff --git a/src/cmd/go/alldocs.go b/src/cmd/go/alldocs.go
index e8bfff1e69..47076570a6 100644
--- a/src/cmd/go/alldocs.go
+++ b/src/cmd/go/alldocs.go
@@ -1916,6 +1916,8 @@
 // 		If module-aware mode is disabled, GOMOD will be the empty string.
 // 	GOTOOLDIR
 // 		The directory where the go tools (compile, cover, doc, etc...) are installed.
+// 	GOVERSION
+// 		The version of the installed Go tree, as reported by runtime.Version.
 //
 //
 // File types
diff --git a/src/cmd/go/go_test.go b/src/cmd/go/go_test.go
index ee0cd8e2c7..a02231fa98 100644
--- a/src/cmd/go/go_test.go
+++ b/src/cmd/go/go_test.go
@@ -1886,6 +1886,18 @@ func TestGoEnv(t *testing.T) {
 	tg.grepStdout("gcc", "CC not found")
 	tg.run("env", "GOGCCFLAGS")
 	tg.grepStdout("-ffaster", "CC arguments not found")
+
+	tg.run("env", "GOVERSION")
+	envVersion := strings.TrimSpace(tg.stdout.String())
+
+	tg.run("version")
+	cmdVersion := strings.TrimSpace(tg.stdout.String())
+
+	// If 'go version' is "go version <version> <goos>/<goarch>", then
+	// 'go env GOVERSION' is just "<version>".
+	if cmdVersion == envVersion || !strings.Contains(cmdVersion, envVersion) {
+		t.Fatalf("'go env GOVERSION' %q should be a shorter substring of 'go version' %q", envVersion, cmdVersion)
+	}
 }
 
 const (
diff --git a/src/cmd/go/internal/envcmd/env.go b/src/cmd/go/internal/envcmd/env.go
index d65ace879d..46af36eb11 100644
--- a/src/cmd/go/internal/envcmd/env.go
+++ b/src/cmd/go/internal/envcmd/env.go
@@ -88,6 +88,7 @@ func MkEnv() []cfg.EnvVar {
 		{Name: "GOTMPDIR", Value: cfg.Getenv("GOTMPDIR")},
 		{Name: "GOTOOLDIR", Value: base.ToolDir},
 		{Name: "GOVCS", Value: cfg.GOVCS},
+		{Name: "GOVERSION", Value: runtime.Version()},
 	}
 
 	if work.GccgoBin != "" {
@@ -399,7 +400,7 @@ func getOrigEnv(key string) string {
 
 func checkEnvWrite(key, val string) error {
 	switch key {
-	case "GOEXE", "GOGCCFLAGS", "GOHOSTARCH", "GOHOSTOS", "GOMOD", "GOTOOLDIR":
+	case "GOEXE", "GOGCCFLAGS", "GOHOSTARCH", "GOHOSTOS", "GOMOD", "GOTOOLDIR", "GOVERSION":
 		return fmt.Errorf("%s cannot be modified", key)
 	case "GOENV":
 		return fmt.Errorf("%s can only be set using the OS environment", key)
diff --git a/src/cmd/go/internal/help/helpdoc.go b/src/cmd/go/internal/help/helpdoc.go
index 50cf911407..98f58441b4 100644
--- a/src/cmd/go/internal/help/helpdoc.go
+++ b/src/cmd/go/internal/help/helpdoc.go
@@ -632,6 +632,8 @@ Additional information available from 'go env' but not read from the environment
 		If module-aware mode is disabled, GOMOD will be the empty string.
 	GOTOOLDIR
 		The directory where the go tools (compile, cover, doc, etc...) are installed.
+	GOVERSION
+		The version of the installed Go tree, as reported by runtime.Version.
 	`,
 }
 
diff --git a/src/cmd/go/testdata/script/env_write.txt b/src/cmd/go/testdata/script/env_write.txt
index 0af22ed421..bda1e57826 100644
--- a/src/cmd/go/testdata/script/env_write.txt
+++ b/src/cmd/go/testdata/script/env_write.txt
@@ -69,6 +69,8 @@ go env -u GOPATH
 stderr 'unknown go command variable GODEBUG'
 ! go env -w GOEXE=.bat
 stderr 'GOEXE cannot be modified'
+! go env -w GOVERSION=customversion
+stderr 'GOVERSION cannot be modified'
 ! go env -w GOENV=/env
 stderr 'GOENV can only be set using the OS environment'