tests: fix check to enable the race detector in supported platforms (#…

…40764)

* tests: fix check to enable the race detector in supported platforms

This code is almost 4 years old, the support for the race detector was
lacking at that point and Elastic had its first steps with arm64 builds of Beats.

I updated the check to allow tests to run with RACE_DETECTOR=true in supported
platforms, this includes linux/arm64 and darwin/arm64.

* add log if race is enabled for an unsupported platform

dev-tools/mage/gotest.go

@@ -27,6 +27,7 @@ import (
 	"os/exec"
 	"path"
 	"path/filepath"
+	"slices"
 	"strings"
 	"time"
 
@@ -273,10 +274,20 @@ func GoTest(ctx context.Context, params GoTestArgs) error {
 
 	var testArgs []string
 
-	// -race is only supported on */amd64
-	if os.Getenv("DEV_ARCH") == "amd64" {
-		if params.Race {
+	if params.Race {
+		// Enable the race detector for supported platforms.
+		// This is an intersection of the supported platforms for Beats and Go.
+		//
+		// See https://go.dev/doc/articles/race_detector#Requirements.
+		devOS := os.Getenv("DEV_OS")
+		devArch := os.Getenv("DEV_ARCH")
+		raceAmd64 := devArch == "amd64"
+		raceArm64 := devArch == "arm64" &&
+			slices.Contains([]string{"linux", "darwin"}, devOS)
+		if raceAmd64 || raceArm64 {
 			testArgs = append(testArgs, "-race")
+		} else {
+			log.Printf("Warning: skipping -race flag for unsupported platform %s/%s\n", devOS, devArch)
 		}
 	}
 	if len(params.Tags) > 0 {