diff --git a/ui/build/build.go b/ui/build/build.go
index edc595d..6874ef7 100644
--- a/ui/build/build.go
+++ b/ui/build/build.go
@@ -259,10 +259,16 @@
 		startGoma(ctx, config)
 	}
 
+	rbeCh := make(chan bool)
 	if config.StartRBE() {
 		cleanupRBELogsDir(ctx, config)
-		startRBE(ctx, config)
+		go func() {
+			startRBE(ctx, config)
+			close(rbeCh)
+		}()
 		defer DumpRBEMetrics(ctx, config, filepath.Join(config.LogsDir(), "rbe_metrics.pb"))
+	} else {
+		close(rbeCh)
 	}
 
 	if what&RunProductConfig != 0 {
@@ -315,11 +321,11 @@
 		testForDanglingRules(ctx, config)
 	}
 
+	<-rbeCh
 	if what&RunNinja != 0 {
 		if what&RunKati != 0 {
 			installCleanIfNecessary(ctx, config)
 		}
-
 		runNinjaForBuild(ctx, config)
 	}
 
diff --git a/ui/build/config.go b/ui/build/config.go
index a755d14..bf4aec9 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -1374,6 +1374,15 @@
 	return filepath.Join(buildTmpDir, "rbe")
 }
 
+func (c *configImpl) rbeCacheDir() string {
+	for _, f := range []string{"RBE_cache_dir", "FLAG_cache_dir"} {
+		if v, ok := c.environ.Get(f); ok {
+			return v
+		}
+	}
+	return shared.JoinPath(c.SoongOutDir(), "rbe")
+}
+
 func (c *configImpl) shouldCleanupRBELogsDir() bool {
 	// Perform a log directory cleanup only when the log directory
 	// is auto created by the build rather than user-specified.
diff --git a/ui/build/rbe.go b/ui/build/rbe.go
index 1d17216..6479925 100644
--- a/ui/build/rbe.go
+++ b/ui/build/rbe.go
@@ -60,6 +60,7 @@
 		"RBE_exec_root":     config.rbeExecRoot(),
 		"RBE_output_dir":    config.rbeProxyLogsDir(),
 		"RBE_proxy_log_dir": config.rbeProxyLogsDir(),
+		"RBE_cache_dir":     config.rbeCacheDir(),
 		"RBE_platform":      "container-image=" + remoteexec.DefaultImage,
 	}
 	if config.StartRBE() {