diff --git a/src/androidtest.bash b/src/androidtest.bash
index e43b89c0dcadc..12f240cc5807e 100755
--- a/src/androidtest.bash
+++ b/src/androidtest.bash
@@ -31,14 +31,11 @@ fi
 export CGO_ENABLED=1
 unset GOBIN
 
-# Do the build first, so we can build go_android_exec and cleaner.
+# Do the build first, so we can build the 'cleaner' binary.
 # Also lets us fail early before the (slow) adb push if the build is broken.
 . ./make.bash --no-banner
 export GOROOT=$(dirname $(pwd))
 export PATH=$GOROOT/bin:$PATH
-GOOS=$GOHOSTOS GOARCH=$GOHOSTARCH go build \
-	-o ../bin/go_android_${GOARCH}_exec \
-	../misc/android/go_android_exec.go
 
 export pkgdir=$(dirname $(go list -f '{{.Target}}' runtime))
 if [ "$pkgdir" = "" ]; then
diff --git a/src/cmd/dist/build.go b/src/cmd/dist/build.go
index ad2c96436a069..6388e3e863287 100644
--- a/src/cmd/dist/build.go
+++ b/src/cmd/dist/build.go
@@ -1366,14 +1366,42 @@ func cmdbootstrap() {
 	// Remove go_bootstrap now that we're done.
 	xremove(pathf("%s/go_bootstrap", tooldir))
 
+	// Build the exec wrapper if necessary.
+	if wrapperPath := wrapperPathFor(goos, goarch); wrapperPath != "" {
+		oldcc := os.Getenv("CC")
+		os.Setenv("GOOS", gohostos)
+		os.Setenv("GOARCH", gohostarch)
+		os.Setenv("CC", compilerEnvLookup(defaultcc, gohostos, gohostarch))
+		goCmd(cmdGo, "build", "-o", pathf("%s/go_%s_%s_exec%s", gobin, goos, goarch, exe), wrapperPath)
+		// Restore environment.
+		// TODO(elias.naur): support environment variables in goCmd?
+		os.Setenv("GOOS", goos)
+		os.Setenv("GOARCH", goarch)
+		os.Setenv("CC", oldcc)
+	}
+
 	// Print trailing banner unless instructed otherwise.
 	if !noBanner {
 		banner()
 	}
 }
 
+func wrapperPathFor(goos, goarch string) string {
+	switch {
+	case goos == "android":
+		return pathf("%s/misc/android/go_android_exec.go", goroot)
+	case goos == "darwin" && (goarch == "arm" || goarch == "arm64"):
+		return pathf("%s/misc/ios/go_darwin_arm_exec.go", goroot)
+	}
+	return ""
+}
+
 func goInstall(goBinary string, args ...string) {
-	installCmd := []string{goBinary, "install", "-gcflags=all=" + gogcflags, "-ldflags=all=" + goldflags}
+	goCmd(goBinary, "install", args...)
+}
+
+func goCmd(goBinary string, cmd string, args ...string) {
+	installCmd := []string{goBinary, cmd, "-gcflags=all=" + gogcflags, "-ldflags=all=" + goldflags}
 	if vflag > 0 {
 		installCmd = append(installCmd, "-v")
 	}
diff --git a/src/iostest.bash b/src/iostest.bash
index b402ff0792c3a..1fc1666bae221 100755
--- a/src/iostest.bash
+++ b/src/iostest.bash
@@ -56,14 +56,10 @@ export PATH=$GOROOT/bin:$PATH
 export CGO_ENABLED=1
 export CC_FOR_TARGET=$GOROOT/misc/ios/clangwrap.sh
 
-# Run the build for the host bootstrap, so we can build go_darwin_arm_exec.
+# Run the build for the host bootstrap, so we can build detect.go.
 # Also lets us fail early before the (slow) ios-deploy if the build is broken.
 ./make.bash
 
-GOOS=$GOHOSTOS GOARCH=$GOHOSTARCH go build \
-	-o ../bin/go_darwin_${GOARCH}_exec \
-	../misc/ios/go_darwin_arm_exec.go
-
 if [ "$GOIOS_DEV_ID" = "" ]; then
 	echo "detecting iOS development identity"
 	eval $(GOOS=$GOHOSTOS GOARCH=$GOHOSTARCH go run ../misc/ios/detect.go)