diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index 22077c70..50bec03a 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -16,11 +16,19 @@ jobs:
     steps:
     - uses: actions/checkout@v3
 
+    - name: Prepare typo config
+      run: |
+        # Don't correct the word "Incrimental"
+        echo -ne '[files]\nextend-exclude = ["**/vendir/**/*"]\n[default.extend-words]\nIncrimental = "Incrimental"\n' > /tmp/typo-config.toml
+        cat /tmp/typo-config.toml
+
     - name: Check spelling of files
       uses: crate-ci/typos@master
       continue-on-error: false
       with: 
         files: ./
+        config: /tmp/typo-config.toml
+        isolated: true
 
     - name: Set up Go1.17
       uses: actions/setup-go@v4
diff --git a/cmd/xgo/exec_tool/debug.go b/cmd/xgo/exec_tool/debug.go
index d506a006..3de50e64 100644
--- a/cmd/xgo/exec_tool/debug.go
+++ b/cmd/xgo/exec_tool/debug.go
@@ -50,6 +50,7 @@ func getDebugEnvList(xgoCompilerEnableEnv string) [][2]string {
 		// strace
 		{XGO_STACK_TRACE, os.Getenv(XGO_STACK_TRACE)},
 		{XGO_STACK_TRACE_DIR, os.Getenv(XGO_STACK_TRACE_DIR)},
+		{XGO_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT, os.Getenv(XGO_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT)},
 
 		{XGO_STD_LIB_TRAP_DEFAULT_ALLOW, os.Getenv(XGO_STD_LIB_TRAP_DEFAULT_ALLOW)},
 		{XGO_DEBUG_COMPILE_PKG, os.Getenv(XGO_DEBUG_COMPILE_PKG)},
diff --git a/cmd/xgo/exec_tool/env.go b/cmd/xgo/exec_tool/env.go
index 68d7e207..f940987c 100644
--- a/cmd/xgo/exec_tool/env.go
+++ b/cmd/xgo/exec_tool/env.go
@@ -20,6 +20,9 @@ const XGO_STACK_TRACE = "XGO_STACK_TRACE"
 // --strace-dir
 const XGO_STACK_TRACE_DIR = "XGO_STACK_TRACE_DIR"
 
+// --strace-snapshot-main-module-default
+const XGO_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT = "XGO_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT"
+
 const XGO_COMPILE_PKG_DATA_DIR = "XGO_COMPILE_PKG_DATA_DIR"
 
 const XGO_STD_LIB_TRAP_DEFAULT_ALLOW = "XGO_STD_LIB_TRAP_DEFAULT_ALLOW"
diff --git a/cmd/xgo/main.go b/cmd/xgo/main.go
index 6b56d25d..76a41fab 100644
--- a/cmd/xgo/main.go
+++ b/cmd/xgo/main.go
@@ -168,6 +168,7 @@ func handleBuild(cmd string, args []string) error {
 	dumpAST := opts.dumpAST
 	stackTrace := opts.stackTrace
 	stackTraceDir := opts.stackTraceDir
+	straceSnapshotMainModuleDefault := opts.straceSnapshotMainModuleDefault
 	trapStdlib := opts.trapStdlib
 
 	if cmdExec && len(remainArgs) == 0 {
@@ -293,7 +294,9 @@ func handleBuild(cmd string, args []string) error {
 		h.Write(optionsFromFileContent)
 		buildCacheSuffix += "-" + hex.EncodeToString(h.Sum(nil))
 	}
+	var enableStackTrace bool
 	if stackTrace == "on" || stackTrace == "true" {
+		enableStackTrace = true
 		v := stackTrace
 		if v == "true" {
 			v = "on"
@@ -660,6 +663,9 @@ func handleBuild(cmd string, args []string) error {
 		if stackTraceDir != "" {
 			execCmd.Env = append(execCmd.Env, exec_tool.XGO_STACK_TRACE_DIR+"="+stackTraceDir)
 		}
+		if enableStackTrace && straceSnapshotMainModuleDefault != "" {
+			execCmd.Env = append(execCmd.Env, exec_tool.XGO_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT+"="+straceSnapshotMainModuleDefault)
+		}
 
 		// trap stdlib
 		var trapStdlibEnv string
diff --git a/cmd/xgo/option.go b/cmd/xgo/option.go
index fb588382..64af194f 100644
--- a/cmd/xgo/option.go
+++ b/cmd/xgo/option.go
@@ -77,6 +77,8 @@ type options struct {
 	stackTrace string
 	// --strace-dir
 	stackTraceDir string
+	// --strace-snapshot-main-module-default
+	straceSnapshotMainModuleDefault string
 
 	remainArgs []string
 
@@ -129,6 +131,7 @@ func parseOptions(cmd string, args []string) (*options, error) {
 	var modfile string
 	var stackTrace string
 	var stackTraceDir string
+	var straceSnapshotMainModuleDefault string
 	var trapStdlib bool
 
 	var remainArgs []string
@@ -358,6 +361,11 @@ func parseOptions(cmd string, args []string) (*options, error) {
 			stackTrace = argVal
 			continue
 		}
+		stackTraceMainModuleDefaultFlag, val := flag.TrySingleFlag([]string{"--strace-snapshot-main-module-default"}, arg)
+		if stackTraceMainModuleDefaultFlag != "" {
+			straceSnapshotMainModuleDefault = val
+			continue
+		}
 
 		// supported flag: --trap-stdlib, --trap-stdlib=false, --trap-stdlib=true
 		trapStdlibFlag, trapStdlibVal := flag.TrySingleFlag([]string{"--trap-stdlib"}, arg)
@@ -458,13 +466,14 @@ func parseOptions(cmd string, args []string) (*options, error) {
 		// default true
 		syncWithLink: syncWithLink == nil || *syncWithLink,
 
-		mod:           mod,
-		gcflags:       gcflags,
-		overlay:       overlay,
-		modfile:       modfile,
-		stackTrace:    stackTrace,
-		stackTraceDir: stackTraceDir,
-		trapStdlib:    trapStdlib,
+		mod:                             mod,
+		gcflags:                         gcflags,
+		overlay:                         overlay,
+		modfile:                         modfile,
+		stackTrace:                      stackTrace,
+		stackTraceDir:                   stackTraceDir,
+		straceSnapshotMainModuleDefault: straceSnapshotMainModuleDefault,
+		trapStdlib:                      trapStdlib,
 
 		remainArgs: remainArgs,
 		testArgs:   testArgs,
diff --git a/cmd/xgo/runtime_gen/trace/trace.go b/cmd/xgo/runtime_gen/trace/trace.go
index 1dfd9baa..3a84041a 100755
--- a/cmd/xgo/runtime_gen/trace/trace.go
+++ b/cmd/xgo/runtime_gen/trace/trace.go
@@ -5,7 +5,9 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"runtime/debug"
 	"strconv"
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -27,7 +29,18 @@ type testInfo struct {
 	onFinish func()
 }
 
+var effectMainModule string
+
 func init() {
+	if flags.MAIN_MODULE != "" {
+		// fmt.Fprintf(os.Stderr, "DEBUG main module from flags: %s\n", flags.MAIN_MODULE)
+		effectMainModule = flags.MAIN_MODULE
+	} else {
+		buildInfo, _ := debug.ReadBuildInfo()
+		if buildInfo != nil {
+			effectMainModule = buildInfo.Main.Path
+		}
+	}
 	__xgo_link_on_test_start(func(t *testing.T, fn func(t *testing.T)) {
 		name := t.Name()
 		if name == "" {
@@ -268,6 +281,15 @@ func handleTracePre(ctx context.Context, f *core.FuncInfo, args core.Object, res
 				break
 			}
 		}
+
+		// check if allow main module to be defaultly snapshoted
+		if !anySnapshot && flags.STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT != "false" && effectMainModule != "" && strings.HasPrefix(f.Pkg, effectMainModule) {
+			// main_module or main_module/*
+			if len(f.Pkg) == len(effectMainModule) || f.Pkg[len(effectMainModule)] == '/' {
+				// fmt.Fprintf(os.Stderr, "DEBUG main module snapshot: %s of %s\n", f.Pkg, effectMainModule)
+				anySnapshot = true
+			}
+		}
 		if anySnapshot {
 			stack.Snapshot = true
 			stack.Args = premarshal(stack.Args)
diff --git a/cmd/xgo/runtime_gen/trap/flags/flags.go b/cmd/xgo/runtime_gen/trap/flags/flags.go
index b3aaf24e..b8bf1127 100755
--- a/cmd/xgo/runtime_gen/trap/flags/flags.go
+++ b/cmd/xgo/runtime_gen/trap/flags/flags.go
@@ -1,5 +1,17 @@
 package flags
 
+// to inject these flags, see patch/syntax/syntax.go, search for flag_MAIN_MODULE
+// this package exists to make flags passed to xgo to be persisted in building and running.
+
+// flag: none
+// env: XGO_MAIN_MODULE
+// description:
+//
+//	auto detected by xgo in the beginning of building.
+//	can be used prior to ask runtime/debug's info:
+//	var mainModulePath = runtime/debug.ReadBuildInfo().Main.Path
+const MAIN_MODULE = ""
+
 // flag: --strace
 // env: XGO_STACK_TRACE
 // description:
@@ -21,6 +33,21 @@ const STRACE = ""
 //	directory, default current dir
 const STRACE_DIR = ""
 
+// flag: --strace-snapshot-main-module
+// env: XGO_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT
+// description:
+//
+//	collecting main module's trace in snapshot mode,
+//	while other's are non snapshot mode
+//
+//	snapshot mode: args are serialized before executing
+//	the function, and results are serilaized after return.
+//	this is useful if an object will be modified in later
+//	process.
+//
+// values: true or false
+const STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT = ""
+
 // flag: --trap-stdlib
 // env: XGO_STD_LIB_TRAP_DEFAULT_ALLOW
 // description: if true, stdlib trap is by default allowed
diff --git a/cmd/xgo/trace.go b/cmd/xgo/trace.go
index 2d857f9a..ffd2b15e 100644
--- a/cmd/xgo/trace.go
+++ b/cmd/xgo/trace.go
@@ -29,6 +29,10 @@ type importResult struct {
 var runtimeGenFS embed.FS
 
 // TODO: may apply tags
+// importRuntimeDep detect if the target package already
+// has github.com/xhd2015/xgo/runtime as dependency,
+// if not, dynamically modify the go.mod to include that,
+// and add a blank import in the main package
 func importRuntimeDep(test bool, goroot string, goBinary string, goVersion *goinfo.GoVersion, absModFile string, xgoSrc string, projectDir string, modRootRel []string, mainModule string, mod string, args []string) (*importResult, error) {
 	if mainModule == "" {
 		// only work with module
@@ -64,7 +68,6 @@ func importRuntimeDep(test bool, goroot string, goBinary string, goVersion *goin
 		return nil, err
 	}
 
-	pkgArgs := getPkgArgs(args)
 	tmpRoot, tmpProjectDir, err := createWorkDir(projectRoot)
 	if err != nil {
 		return nil, err
@@ -84,6 +87,7 @@ func importRuntimeDep(test bool, goroot string, goBinary string, goVersion *goin
 		}
 	}
 
+	pkgArgs := getPkgArgs(args)
 	fileReplace, err := addBlankImports(goroot, goBinary, projectDir, pkgArgs, test, tmpProjectDir)
 	if err != nil {
 		return nil, err
@@ -171,8 +175,10 @@ type Overlay struct {
 
 type dependencyInfo struct {
 	modReplace map[string]string
-	mod        string
-	modfile    string // alternative go.mod
+	// the -mod flag
+	mod string
+	// the -modfile flag
+	modfile string // alternative go.mod
 }
 
 func createWorkDir(projectRoot string) (tmpRoot string, tmpProjectDir string, err error) {
diff --git a/cmd/xgo/version.go b/cmd/xgo/version.go
index 3e528af0..c7653b52 100644
--- a/cmd/xgo/version.go
+++ b/cmd/xgo/version.go
@@ -6,8 +6,8 @@ import "fmt"
 // VERSION is manually updated when needed a new tag
 // see also runtime/core/version.go
 const VERSION = "1.0.51"
-const REVISION = "f43d1801162be8396dd5b73a27b529253a121a88+1"
-const NUMBER = 319
+const REVISION = "38209d904dbe681a458641ad5e7f1c408c8a3626+1"
+const NUMBER = 320
 
 // the matching runtime/core's version
 // manually updated
diff --git a/doc/test-explorer/README.md b/doc/test-explorer/README.md
index f6151287..88089d5f 100644
--- a/doc/test-explorer/README.md
+++ b/doc/test-explorer/README.md
@@ -20,7 +20,7 @@ An example config:
     "env":{
         "TEST_WITH_XGO":"true"
     },
-    "flags":["-p=12"],
+    "flags":["-p=4"],
     "args":["--my-program-env","TEST"],
     "mock_rules":[{
         "stdlib": true,
@@ -149,10 +149,17 @@ Definition:
 Definition:
 ```json
 {
-    "disabled": true
+    "disabled": true|false,
+    "diff_with": "origin/master",
+    "include": [...],
+    "exclude": [...]
 }
 ```
 
 By default, if `coverage` is missing or `null`, then coverage is enabled.
 
+If set `diff_with` to `none`, then incremental coverage will be disabled.
+
+`include` and `exclude` specify which files will be included or excluded in coverage display.
+
 Setting `"coverage": false` or `"coverage":{"disabled": true}` will disable it.
\ No newline at end of file
diff --git a/patch/syntax/syntax.go b/patch/syntax/syntax.go
index 0ad01b2b..e23b021a 100644
--- a/patch/syntax/syntax.go
+++ b/patch/syntax/syntax.go
@@ -30,9 +30,12 @@ const XGO_VERSION = "XGO_VERSION"
 const XGO_REVISION = "XGO_REVISION"
 const XGO_NUMBER = "XGO_NUMBER"
 
+const XGO_MAIN_MODULE = "XGO_MAIN_MODULE"
+
 // --strace
 const XGO_STACK_TRACE = "XGO_STACK_TRACE"
 const XGO_STACK_TRACE_DIR = "XGO_STACK_TRACE_DIR"
+const XGO_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT = "XGO_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT"
 const XGO_STD_LIB_TRAP_DEFAULT_ALLOW = "XGO_STD_LIB_TRAP_DEFAULT_ALLOW"
 
 // Deprecated: use flag_STRACE,.. instead
@@ -40,10 +43,14 @@ const straceFlagConstName = "__xgo_injected_StraceFlag"
 const trapStdlibFlagConstName = "__xgo_injected_StdlibTrapDefaultAllow"
 
 const (
+	// auto detected
+	flag_MAIN_MODULE = "MAIN_MODULE"
 	// --strace
 	flag_STRACE = "STRACE"
 	// --strace-dir
 	flag_STRACE_DIR = "STRACE_DIR"
+	// --strace-snapshot-main-module
+	flag_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT = "STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT"
 	// --trap-stdlib
 	flag_TRAP_STDLIB = "TRAP_STDLIB"
 )
@@ -454,10 +461,14 @@ func injectXgoGeneralFlags(fileList []*syntax.File) {
 		forEachConst(file.DeclList, func(constDecl *syntax.ConstDecl) bool {
 			for _, name := range constDecl.NameList {
 				switch name.Value {
+				case flag_MAIN_MODULE:
+					constDecl.Values = newStringLit(os.Getenv(XGO_MAIN_MODULE))
 				case flag_STRACE:
 					constDecl.Values = newStringLit(os.Getenv(XGO_STACK_TRACE))
 				case flag_STRACE_DIR:
 					constDecl.Values = newStringLit(os.Getenv(XGO_STACK_TRACE_DIR))
+				case flag_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT:
+					constDecl.Values = newStringLit(os.Getenv(XGO_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT))
 				case flag_TRAP_STDLIB:
 					constDecl.Values = newStringLit(os.Getenv(XGO_STD_LIB_TRAP_DEFAULT_ALLOW))
 				}
diff --git a/runtime/test/stack_trace/snapshot_main_default/trace_snapshot_main_default_test.go b/runtime/test/stack_trace/snapshot_main_default/trace_snapshot_main_default_test.go
new file mode 100644
index 00000000..c53055cf
--- /dev/null
+++ b/runtime/test/stack_trace/snapshot_main_default/trace_snapshot_main_default_test.go
@@ -0,0 +1,9 @@
+package snapshot_main_default
+
+import "testing"
+
+func TestSnapshotMainDefault(t *testing.T) {
+	// TODO: I forgot how to write test against trace
+	// see https://github.com/xhd2015/xgo/issues/281#issuecomment-2466153734
+	// for test detail
+}
diff --git a/runtime/test/trace/snapshot/snapshot_test.go b/runtime/test/trace/snapshot/snapshot_test.go
index bbd4191b..ec01c68e 100644
--- a/runtime/test/trace/snapshot/snapshot_test.go
+++ b/runtime/test/trace/snapshot/snapshot_test.go
@@ -13,6 +13,12 @@ import (
 // NOTE: do not run with -cover, because
 // extra function will be included in trace
 
+// TODO: this test currently fails, but
+// it is not so urgent to fix it, so
+// I'll keep it here.
+// once I got enough time to do, I'll
+// try my best.
+// see related https://github.com/xhd2015/xgo/issues/281
 func TestNoSnapshot(t *testing.T) {
 	test(t, noSnapshotExpect, nil)
 }
diff --git a/runtime/trace/trace.go b/runtime/trace/trace.go
index 1dfd9baa..3a84041a 100644
--- a/runtime/trace/trace.go
+++ b/runtime/trace/trace.go
@@ -5,7 +5,9 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"runtime/debug"
 	"strconv"
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -27,7 +29,18 @@ type testInfo struct {
 	onFinish func()
 }
 
+var effectMainModule string
+
 func init() {
+	if flags.MAIN_MODULE != "" {
+		// fmt.Fprintf(os.Stderr, "DEBUG main module from flags: %s\n", flags.MAIN_MODULE)
+		effectMainModule = flags.MAIN_MODULE
+	} else {
+		buildInfo, _ := debug.ReadBuildInfo()
+		if buildInfo != nil {
+			effectMainModule = buildInfo.Main.Path
+		}
+	}
 	__xgo_link_on_test_start(func(t *testing.T, fn func(t *testing.T)) {
 		name := t.Name()
 		if name == "" {
@@ -268,6 +281,15 @@ func handleTracePre(ctx context.Context, f *core.FuncInfo, args core.Object, res
 				break
 			}
 		}
+
+		// check if allow main module to be defaultly snapshoted
+		if !anySnapshot && flags.STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT != "false" && effectMainModule != "" && strings.HasPrefix(f.Pkg, effectMainModule) {
+			// main_module or main_module/*
+			if len(f.Pkg) == len(effectMainModule) || f.Pkg[len(effectMainModule)] == '/' {
+				// fmt.Fprintf(os.Stderr, "DEBUG main module snapshot: %s of %s\n", f.Pkg, effectMainModule)
+				anySnapshot = true
+			}
+		}
 		if anySnapshot {
 			stack.Snapshot = true
 			stack.Args = premarshal(stack.Args)
diff --git a/runtime/trap/flags/flags.go b/runtime/trap/flags/flags.go
index b3aaf24e..b8bf1127 100644
--- a/runtime/trap/flags/flags.go
+++ b/runtime/trap/flags/flags.go
@@ -1,5 +1,17 @@
 package flags
 
+// to inject these flags, see patch/syntax/syntax.go, search for flag_MAIN_MODULE
+// this package exists to make flags passed to xgo to be persisted in building and running.
+
+// flag: none
+// env: XGO_MAIN_MODULE
+// description:
+//
+//	auto detected by xgo in the beginning of building.
+//	can be used prior to ask runtime/debug's info:
+//	var mainModulePath = runtime/debug.ReadBuildInfo().Main.Path
+const MAIN_MODULE = ""
+
 // flag: --strace
 // env: XGO_STACK_TRACE
 // description:
@@ -21,6 +33,21 @@ const STRACE = ""
 //	directory, default current dir
 const STRACE_DIR = ""
 
+// flag: --strace-snapshot-main-module
+// env: XGO_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT
+// description:
+//
+//	collecting main module's trace in snapshot mode,
+//	while other's are non snapshot mode
+//
+//	snapshot mode: args are serialized before executing
+//	the function, and results are serilaized after return.
+//	this is useful if an object will be modified in later
+//	process.
+//
+// values: true or false
+const STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT = ""
+
 // flag: --trap-stdlib
 // env: XGO_STD_LIB_TRAP_DEFAULT_ALLOW
 // description: if true, stdlib trap is by default allowed
diff --git a/script/run-test/main.go b/script/run-test/main.go
index 4df10149..b0c6be41 100644
--- a/script/run-test/main.go
+++ b/script/run-test/main.go
@@ -9,6 +9,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/xhd2015/xgo/cmd/xgo/exec_tool"
 	"github.com/xhd2015/xgo/support/cmd"
 )
 
@@ -149,6 +150,9 @@ var extraSubTests = []*TestCase{
 		name:        "trace-snapshot",
 		dir:         "runtime/test/trace/snapshot",
 		skipOnCover: true,
+		// TODO: let program configure it
+		env: []string{exec_tool.XGO_STRACE_SNAPSHOT_MAIN_MODULE_DEFAULT + "=false"},
+		// flags:       []string{"--strace-snapshot-main-module-default=false"},
 	},
 	{
 		name: "trace-custom-dir",