diff --git a/compiler/cmd/internal/version/version.go b/compiler/cmd/internal/version/version.go
index 9caf7cb2..75bba7a1 100644
--- a/compiler/cmd/internal/version/version.go
+++ b/compiler/cmd/internal/version/version.go
@@ -21,7 +21,7 @@ import (
 	"runtime"
 
 	"github.com/goplus/llgo/compiler/cmd/internal/base"
-	"github.com/goplus/llgo/x/env"
+	"github.com/goplus/llgo/compiler/internal/env"
 )
 
 // llgo version
diff --git a/x/env/build.go b/compiler/internal/env/build.go
similarity index 100%
rename from x/env/build.go
rename to compiler/internal/env/build.go
diff --git a/compiler/internal/env/env.go b/compiler/internal/env/env.go
index 6eef99be..1088de59 100644
--- a/compiler/internal/env/env.go
+++ b/compiler/internal/env/env.go
@@ -2,9 +2,11 @@ package env
 
 import (
 	"bytes"
+	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 	"strings"
 )
 
@@ -12,6 +14,7 @@ const (
 	LLGoCompilerPkg    = "github.com/goplus/llgo"
 	LLGoRuntimePkgName = "runtime"
 	LLGoRuntimePkg     = LLGoCompilerPkg + "/" + LLGoRuntimePkgName
+	envFileName        = "/compiler/internal/env/env.go"
 )
 
 func GOROOT() string {
@@ -53,13 +56,22 @@ func LLGoROOT() string {
 	}
 	// Check if parent directory is bin
 	dir := filepath.Dir(exe)
-	if filepath.Base(dir) != "bin" {
-		return ""
+	if filepath.Base(dir) == "bin" {
+		// Get parent directory of bin
+		root := filepath.Dir(dir)
+		if root, ok := isLLGoRoot(root); ok {
+			return root
+		}
 	}
-	// Get parent directory of bin
-	root := filepath.Dir(dir)
-	if root, ok := isLLGoRoot(root); ok {
-		return root
+	if Devel() {
+		root, err := getRuntimePkgDirByCaller()
+		if err != nil {
+			return ""
+		}
+		if root, ok := isLLGoRoot(root); ok {
+			fmt.Fprintln(os.Stderr, "WARNING: Using LLGO root for devel: "+root)
+			return root
+		}
 	}
 	return ""
 }
@@ -83,3 +95,22 @@ func isLLGoRoot(root string) (string, bool) {
 	}
 	return root, true
 }
+
+func getRuntimePkgDirByCaller() (string, error) {
+	_, file, _, ok := runtime.Caller(0)
+	if !ok {
+		return "", fmt.Errorf("cannot get caller")
+	}
+	if !strings.HasSuffix(file, envFileName) {
+		return "", fmt.Errorf("wrong caller")
+	}
+	// check file exists
+	if _, err := os.Stat(file); os.IsNotExist(err) {
+		return "", fmt.Errorf("file %s not exists", file)
+	}
+	modPath := strings.TrimSuffix(file, envFileName)
+	if st, err := os.Stat(modPath); os.IsNotExist(err) || !st.IsDir() {
+		return "", fmt.Errorf("not llgo compiler root: %s", modPath)
+	}
+	return modPath, nil
+}
diff --git a/compiler/internal/env/env_test.go b/compiler/internal/env/env_test.go
index 14a49808..0bb19cdb 100644
--- a/compiler/internal/env/env_test.go
+++ b/compiler/internal/env/env_test.go
@@ -58,8 +58,10 @@ func TestLLGoRuntimeDir(t *testing.T) {
 		defer os.Setenv("LLGO_ROOT", origLLGoRoot)
 
 		os.Setenv("LLGO_ROOT", "/nonexistent/path")
-		if got := LLGoRuntimeDir(); got != "" {
-			t.Errorf("LLGoRuntimeDir() = %v, want empty string", got)
+		wd, _ := os.Getwd()
+		expected, _ := filepath.Abs(filepath.Join(wd, "../../../runtime"))
+		if got := LLGoRuntimeDir(); got != expected {
+			t.Errorf("LLGoRuntimeDir() = %v, want %v", got, expected)
 		}
 	})
 }
diff --git a/x/env/version.go b/compiler/internal/env/version.go
similarity index 92%
rename from x/env/version.go
rename to compiler/internal/env/version.go
index 975d4fef..ea80e2bf 100644
--- a/x/env/version.go
+++ b/compiler/internal/env/version.go
@@ -23,6 +23,8 @@ import "runtime/debug"
 var buildVersion string
 
 // Version returns the version of the running LLGo binary.
+//
+//export LLGoVersion
 func Version() string {
 	if buildVersion != "" {
 		return buildVersion
@@ -33,3 +35,7 @@ func Version() string {
 	}
 	return "(devel)"
 }
+
+func Devel() bool {
+	return Version() == "(devel)"
+}