diff --git a/ui/build/config.go b/ui/build/config.go
index 5085c68..e29d239 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -115,6 +115,11 @@
 
 	// Data source to write ninja weight list
 	ninjaWeightListSource NinjaWeightListSource
+
+	// This file is a detailed dump of all soong-defined modules for debugging purposes.
+	// There's quite a bit of overlap with module-info.json and soong module graph. We
+	// could consider merging them.
+	moduleDebugFile string
 }
 
 type NinjaWeightListSource uint
@@ -273,6 +278,10 @@
 		ret.sandboxConfig.SetSrcDirIsRO(srcDirIsWritable == "false")
 	}
 
+	if os.Getenv("GENERATE_SOONG_DEBUG") == "true" {
+		ret.moduleDebugFile, _ = filepath.Abs(shared.JoinPath(ret.SoongOutDir(), "soong-debug-info.json"))
+	}
+
 	ret.environ.Unset(
 		// We're already using it
 		"USE_SOONG_UI",
@@ -325,6 +334,9 @@
 		"ANDROID_DEV_SCRIPTS",
 		"ANDROID_EMULATOR_PREBUILTS",
 		"ANDROID_PRE_BUILD_PATHS",
+
+		// We read it here already, don't let others share in the fun
+		"GENERATE_SOONG_DEBUG",
 	)
 
 	if ret.UseGoma() || ret.ForceUseGoma() {
diff --git a/ui/build/soong.go b/ui/build/soong.go
index 90c3bfc..a201ac5 100644
--- a/ui/build/soong.go
+++ b/ui/build/soong.go
@@ -204,6 +204,11 @@
 		commonArgs = append(commonArgs, "--build-from-source-stub")
 	}
 
+	if pb.config.moduleDebugFile != "" {
+		commonArgs = append(commonArgs, "--soong_module_debug")
+		commonArgs = append(commonArgs, pb.config.moduleDebugFile)
+	}
+
 	commonArgs = append(commonArgs, "-l", filepath.Join(pb.config.FileListDir(), "Android.bp.list"))
 	invocationEnv := make(map[string]string)
 	if pb.debugPort != "" {