diff --git a/Makefile b/Makefile
index 4c846d5..cd3abbb 100644
--- a/Makefile
+++ b/Makefile
@@ -15,6 +15,7 @@ BIN_DIR=bin
 # Apple's Make uses the parent's PATH to spawn bare recipe commands. On POSIX
 # shells, exec forces lookup through the shell with our exported PATH instead.
 # Native Windows shells must keep plain tool invocations.
+# An explicit GOPATH_BIN (including an empty value) skips Go path discovery.
 RUN_TOOL :=
 ifeq ($(wildcard /dev/null),/dev/null)
     DEVNULL := /dev/null
@@ -38,7 +39,9 @@ ifeq ($(OS),Windows_NT)
         # Windows + POSIX Shell (Git Bash / MSYS2 / Cygwin)
         RUN_TOOL := exec
         # cygpath converts drive-letter paths to the shell's mount layout.
-        GOPATH_BIN := $(shell if command -v cygpath >/dev/null 2>&1; then cygpath -u "$$(go env GOPATH)/bin"; else printf '%s/bin' "$$(go env GOPATH)"; fi)
+        ifeq ($(origin GOPATH_BIN),undefined)
+            GOPATH_BIN := $(shell if command -v cygpath >/dev/null 2>&1; then cygpath -u "$$(go env GOPATH)/bin"; else printf '%s/bin' "$$(go env GOPATH)"; fi)
+        endif
         ifneq ($(shell test -d "$(GOPATH_BIN)" && echo yes),)
             export PATH := $(GOPATH_BIN):$(PATH)
         endif
@@ -52,7 +55,9 @@ ifeq ($(OS),Windows_NT)
     else
         # Windows 原生环境 (cmd.exe / PowerShell)
         # 自动将 Go bin 目录加入 PATH (Windows 环境变量使用分号分隔)
-        GOPATH_BIN := $(shell go env GOPATH 2>$(DEVNULL))\bin
+        ifeq ($(origin GOPATH_BIN),undefined)
+            GOPATH_BIN := $(shell go env GOPATH 2>$(DEVNULL))\bin
+        endif
         ifneq ($(wildcard $(GOPATH_BIN)),)
             export PATH := $(GOPATH_BIN);$(PATH)
         endif
@@ -67,7 +72,9 @@ else
     # Linux / macOS 环境 (POSIX)
     RUN_TOOL := exec
     SHELL_EXT :=
-    GOPATH_BIN := $(shell go env GOPATH 2>$(DEVNULL))/bin
+    ifeq ($(origin GOPATH_BIN),undefined)
+        GOPATH_BIN := $(shell go env GOPATH 2>$(DEVNULL))/bin
+    endif
     ifneq ($(shell test -d "$(GOPATH_BIN)" && echo yes),)
         export PATH := $(GOPATH_BIN):$(PATH)
     endif
diff --git a/cmd/makefile_test.go b/cmd/makefile_test.go
index bade326..3f8ac69 100644
--- a/cmd/makefile_test.go
+++ b/cmd/makefile_test.go
@@ -11,27 +11,17 @@ import (
 	"time"
 )
 
+// Allow subprocess startup on loaded native runners while keeping every fixture bounded.
+const makefileTestTimeout = 30 * time.Second
+
 func TestMakefile_LinuxDryRun(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		t.Skip("requires a POSIX host")
 	}
-	if _, err := exec.LookPath("make"); err != nil {
-		t.Skip("make command not available in environment")
-	}
-
-	targets := []string{"build", "clean", "help", "windows", "linux"}
+	targets := []string{"build", "clean", "windows", "linux"}
 	for _, target := range targets {
 		t.Run(target, func(t *testing.T) {
-			ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
-			defer cancel()
-
-			cmd := exec.CommandContext(ctx, "make", "-n", target)
-			cmd.Dir = ".."
-			out, err := cmd.CombinedOutput()
-			if err != nil {
-				t.Fatalf("make -n %s failed: %v, output: %s", target, err, string(out))
-			}
-			outStr := string(out)
+			outStr := makefileDryRun(t, target)
 
 			switch target {
 			case "build":
@@ -55,21 +45,8 @@ func TestMakefile_LinuxDryRun(t *testing.T) {
 }
 
 func TestMakefile_WindowsDryRun(t *testing.T) {
-	if _, err := exec.LookPath("make"); err != nil {
-		t.Skip("make command not available in environment")
-	}
-
 	t.Run("Windows_NT_build", func(t *testing.T) {
-		ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
-		defer cancel()
-
-		cmd := exec.CommandContext(ctx, "make", "-n", "OS=Windows_NT", "build")
-		cmd.Dir = ".."
-		out, err := cmd.CombinedOutput()
-		if err != nil {
-			t.Fatalf("make -n OS=Windows_NT build failed: %v, output: %s", err, string(out))
-		}
-		outStr := string(out)
+		outStr := makefileDryRun(t, "OS=Windows_NT", "build")
 		if !strings.Contains(outStr, "bin/xops.exe") {
 			t.Fatalf("expected bin/xops.exe with OS=Windows_NT, got: %s", outStr)
 		}
@@ -84,34 +61,14 @@ func TestMakefile_WindowsDryRun(t *testing.T) {
 		if runtime.GOOS == "windows" {
 			t.Skip("requires a POSIX host; native Windows clean is tested separately")
 		}
-		ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
-		defer cancel()
-
-		cmd := exec.CommandContext(ctx, "make", "-n", "OS=Windows_NT", "SHELL=/bin/bash", "clean")
-		cmd.Dir = ".."
-		out, err := cmd.CombinedOutput()
-		if err != nil {
-			t.Fatalf("make -n OS=Windows_NT SHELL=/bin/bash clean failed: %v, output: %s", err, string(out))
-		}
-		outStr := string(out)
+		outStr := makefileDryRun(t, "OS=Windows_NT", "SHELL=/bin/bash", "clean")
 		if !strings.Contains(outStr, "rm -rf bin coverage.out") {
 			t.Fatalf("expected rm -rf for POSIX shell on Windows_NT, got: %s", outStr)
 		}
 	})
 
 	t.Run("Windows_NT_CMD_clean", func(t *testing.T) {
-		ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
-		defer cancel()
-
-		// Avoid metadata subprocesses so the CMD dry run also works on POSIX hosts.
-		cmd := exec.CommandContext(ctx, "make", "-n", "OS=Windows_NT", "SHELL=cmd.exe",
-			"GOPATH_BIN=", "VERSION=test", "COMMIT=test", "DATE=test", "clean")
-		cmd.Dir = ".."
-		out, err := cmd.CombinedOutput()
-		if err != nil {
-			t.Fatalf("native Windows clean dry run failed: %v, output: %s", err, out)
-		}
-		outStr := string(out)
+		outStr := makefileDryRun(t, "OS=Windows_NT", "SHELL=cmd.exe", "clean")
 		if !strings.Contains(outStr, "rmdir /s /q bin") {
 			t.Fatalf("expected rmdir /s /q bin for CMD shell on Windows_NT, got: %s", outStr)
 		}
@@ -122,21 +79,7 @@ func TestMakefile_WindowsDryRun(t *testing.T) {
 }
 
 func TestMakefile_CrossCompilationTargets(t *testing.T) {
-	if _, err := exec.LookPath("make"); err != nil {
-		t.Skip("make command not available in environment")
-	}
-
-	ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
-	defer cancel()
-
-	cmd := exec.CommandContext(ctx, "make", "-n", "windows", "windows-arm64", "linux", "linux-arm64", "darwin-amd64", "darwin-arm64")
-	cmd.Dir = ".."
-	out, err := cmd.CombinedOutput()
-	if err != nil {
-		t.Fatalf("make -n cross compilation targets failed: %v, output: %s", err, string(out))
-	}
-
-	outStr := string(out)
+	outStr := makefileDryRun(t, "windows", "windows-arm64", "linux", "linux-arm64", "darwin-amd64", "darwin-arm64")
 	expectedArtifacts := []string{
 		"bin/xops.exe",
 		"bin/xops-arm64.exe",
@@ -153,22 +96,10 @@ func TestMakefile_CrossCompilationTargets(t *testing.T) {
 	}
 }
 
-func TestMakefile_TimeoutContextSafety(t *testing.T) {
-	if _, err := exec.LookPath("make"); err != nil {
-		t.Skip("make command not available in environment")
-	}
-	// Bound make execution even when the suite has no timeout.
-	ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
-	defer cancel()
-
-	start := time.Now()
-	cmd := exec.CommandContext(ctx, "make", "-n", "help")
-	cmd.Dir = ".."
-	if err := cmd.Run(); err != nil {
-		t.Fatalf("make -n help failed: %v", err)
-	}
-	if time.Since(start) > 5*time.Second {
-		t.Fatalf("make -n help took unexpectedly long: %v", time.Since(start))
+func TestMakefile_HelpDryRun(t *testing.T) {
+	out := makefileDryRun(t, "help")
+	if !strings.Contains(out, "make [target]") || !strings.Contains(out, "Targets:") {
+		t.Fatalf("help dry run omitted usage or targets: %s", out)
 	}
 }
 
@@ -199,7 +130,7 @@ func TestMakefile_InstallSkillPOSIX(t *testing.T) {
 				t.Fatal(err)
 			}
 			homeDir := filepath.Join(root, "home with spaces")
-			ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
+			ctx, cancel := context.WithTimeout(t.Context(), makefileTestTimeout)
 			defer cancel()
 			cmd := exec.CommandContext(ctx, "make", "OS="+platform, "SHELL=/bin/sh", "GOPATH_BIN=", "HOME="+homeDir, "install-skill")
 			cmd.Dir = root
@@ -218,21 +149,72 @@ func TestMakefile_InstallSkillPOSIX(t *testing.T) {
 }
 
 func TestMakefile_InstallSkillWindowsDryRun(t *testing.T) {
-	if _, err := exec.LookPath("make"); err != nil {
+	out := makefileDryRun(t, "OS=Windows_NT", "SHELL=cmd.exe", "install-skill")
+	if strings.Count(out, "(Join-Path $HOME '.gemini/skills/xops-agent')") != 2 {
+		t.Fatalf("expected expandable home paths for both installation commands, got: %s", out)
+	}
+}
+
+// Dry runs check recipes with fixed metadata, without measuring Go/Git startup
+// on a loaded native runner. Real tool execution and PATH discovery have separate
+// fixture tests below. Bound both the command and inherited output pipes.
+func makefileDryRun(t *testing.T, args ...string) string {
+	t.Helper()
+	makePath, err := exec.LookPath("make")
+	if err != nil {
 		t.Skip("make command not available in environment")
 	}
-	ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
+	ctx, cancel := context.WithTimeout(t.Context(), makefileTestTimeout)
 	defer cancel()
-	// Override shell-evaluated metadata so this dry run also works on POSIX hosts.
-	cmd := exec.CommandContext(ctx, "make", "-n", "OS=Windows_NT", "SHELL=cmd.exe",
-		"GOPATH_BIN=", "VERSION=test", "COMMIT=test", "DATE=test", "install-skill")
+	options := []string{"-n", "GOPATH_BIN=", "VERSION=test", "COMMIT=test", "DATE=test"}
+	cmd := exec.CommandContext(ctx, makePath, append(options, args...)...)
 	cmd.Dir = ".."
+	cmd.WaitDelay = time.Second
 	out, err := cmd.CombinedOutput()
 	if err != nil {
-		t.Fatalf("Windows install-skill dry run failed: %v, output: %s", err, out)
+		t.Fatalf("make dry run %v failed: %v (context: %v), output: %s", args, err, ctx.Err(), out)
 	}
-	if strings.Count(string(out), "(Join-Path $HOME '.gemini/skills/xops-agent')") != 2 {
-		t.Fatalf("expected expandable home paths for both installation commands, got: %s", out)
+	return string(out)
+}
+
+func TestMakefile_GOPATHOverrideSkipsDiscovery(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("requires a POSIX host for shell fixtures")
+	}
+	makePath, err := exec.LookPath("make")
+	if err != nil {
+		t.Skip("make command not available in environment")
+	}
+	for _, platform := range []struct {
+		name, os, shellMode string
+	}{
+		{"POSIX", "Darwin", "yes"},
+		{"Windows_POSIX", "Windows_NT", "yes"},
+		{"Windows_CMD", "Windows_NT", ""},
+	} {
+		for _, bin := range []string{"", "/explicit go/bin"} {
+			t.Run(platform.name+"/"+bin, func(t *testing.T) {
+				root := makefileFixture(t)
+				marker := filepath.Join(root, "discovery")
+				writeMakefileFixture(t, root, "tools/go", "#!/bin/sh\nprintf 'called' >> \"$XOPS_MAKE_DISCOVERY\"\nprintf '/unused'\n")
+				t.Setenv("PATH", filepath.Join(root, "tools"))
+				t.Setenv("XOPS_MAKE_DISCOVERY", marker)
+				ctx, cancel := context.WithTimeout(t.Context(), makefileTestTimeout)
+				defer cancel()
+				cmd := exec.CommandContext(ctx, makePath, "-n", "OS="+platform.os, "SHELL=/bin/sh",
+					"POSIX_SHELL="+platform.shellMode, "GOPATH_BIN="+bin, "VERSION=test", "COMMIT=test", "DATE=test", "help")
+				cmd.Dir = root
+				cmd.WaitDelay = time.Second
+				if out, err := cmd.CombinedOutput(); err != nil {
+					t.Fatalf("help with explicit GOPATH_BIN failed: %v, output: %s", err, out)
+				}
+				if _, err := os.Stat(marker); err == nil {
+					t.Fatal("explicit GOPATH_BIN still invoked Go discovery")
+				} else if !os.IsNotExist(err) {
+					t.Fatalf("check Go discovery marker: %v", err)
+				}
+			})
+		}
 	}
 }
 
@@ -302,7 +284,7 @@ func TestMakefile_WindowsPOSIXPath(t *testing.T) {
 				gopath = `C:\Go Home`
 			}
 			t.Setenv("FIXTURE_GOPATH", gopath)
-			ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
+			ctx, cancel := context.WithTimeout(t.Context(), makefileTestTimeout)
 			defer cancel()
 			cmd := exec.CommandContext(ctx, makePath, "--no-print-directory", "-f", "probe.mk", "OS=Windows_NT", "SHELL=/bin/sh",
 				"VERSION=test", "COMMIT=test", "DATE=test", "probe")
@@ -343,7 +325,7 @@ func TestMakefile_LintUsesExportedPOSIXPath(t *testing.T) {
 					t.Setenv("FIXTURE_EXIT", "7")
 				}
 				t.Setenv("MAKELEVEL", "1")
-				ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
+				ctx, cancel := context.WithTimeout(t.Context(), makefileTestTimeout)
 				defer cancel()
 				cmd := exec.CommandContext(ctx, makePath, "--no-print-directory", "OS="+platform, "SHELL=/bin/sh", "VERSION=test", "COMMIT=test", "DATE=test", "lint")
 				cmd.Dir = root
@@ -397,7 +379,7 @@ case "$2" in
   *) printf 'unexpected shell command: %s\n' "$2" >&2; exit 1 ;;
 esac
 `)
-	ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
+	ctx, cancel := context.WithTimeout(t.Context(), makefileTestTimeout)
 	defer cancel()
 	cmd := exec.CommandContext(ctx, "make", "-n", "OS=Windows_NT",
 		"SHELL="+filepath.Join(root, "sh.exe"), "GOPATH_BIN=",
diff --git a/docs/en/guide/getting-started.md b/docs/en/guide/getting-started.md
index 6a20b1c..acaefd3 100644
--- a/docs/en/guide/getting-started.md
+++ b/docs/en/guide/getting-started.md
@@ -15,6 +15,8 @@ make build
 
 On Windows, `make build` automatically produces `bin/xops.exe`. You can also cross-build Windows binaries on any platform with `make windows`.
 
+Use `make GOPATH_BIN=/path/to/bin build` to specify the Go tool directory. Setting `GOPATH_BIN=` skips automatic Go tool directory discovery and preserves the existing `PATH`.
+
 ## Initialize configuration
 
 ```bash
diff --git a/docs/guide/getting-started.md b/docs/guide/getting-started.md
index 539d88c..d9d903c 100644
--- a/docs/guide/getting-started.md
+++ b/docs/guide/getting-started.md
@@ -15,6 +15,8 @@ make build
 
 在 Windows 系统上，`make build` 会自动生成 `bin/xops.exe`；亦可在任意平台上通过 `make windows` 交叉编译 Windows 产物。
 
+可用 `make GOPATH_BIN=/path/to/bin build` 指定 Go 工具目录；设置 `GOPATH_BIN=` 会跳过 Go 工具目录的自动探测，并保留现有 `PATH`。
+
 ## 初始化配置
 
 ```bash
diff --git a/go.mod b/go.mod
index d0e0367..d4f44ca 100644
--- a/go.mod
+++ b/go.mod
@@ -9,7 +9,7 @@ require (
 	charm.land/lipgloss/v2 v2.0.5
 	github.com/charmbracelet/colorprofile v0.4.3
 	github.com/charmbracelet/ultraviolet v0.0.0-20260703014108-f5a850f9c2b7
-	github.com/charmbracelet/x/ansi v0.11.7
+	github.com/charmbracelet/x/ansi v0.11.8
 	github.com/charmbracelet/x/conpty v0.2.0
 	github.com/charmbracelet/x/term v0.2.2
 	github.com/charmbracelet/x/termios v0.1.1
diff --git a/go.sum b/go.sum
index 60cd50f..9ee9744 100644
--- a/go.sum
+++ b/go.sum
@@ -20,8 +20,8 @@ github.com/charmbracelet/colorprofile v0.4.3 h1:QPa1IWkYI+AOB+fE+mg/5/4HRMZcaXex
 github.com/charmbracelet/colorprofile v0.4.3/go.mod h1:/zT4BhpD5aGFpqQQqw7a+VtHCzu+zrQtt1zhMt9mR4Q=
 github.com/charmbracelet/ultraviolet v0.0.0-20260703014108-f5a850f9c2b7 h1:3FmWoGNWK4STvqg0O0Aeav2T7rodWJAPeF0QpH+8gFw=
 github.com/charmbracelet/ultraviolet v0.0.0-20260703014108-f5a850f9c2b7/go.mod h1:f/jRa757WUmaOZrbPspXymbg/GnbF+rwe4OLsG7aXYo=
-github.com/charmbracelet/x/ansi v0.11.7 h1:kzv1kJvjg2S3r9KHo8hDdHFQLEqn4RBCb39dAYC84jI=
-github.com/charmbracelet/x/ansi v0.11.7/go.mod h1:9qGpnAVYz+8ACONkZBUWPtL7lulP9No6p1epAihUZwQ=
+github.com/charmbracelet/x/ansi v0.11.8 h1:JMFwp0CgDC2+jcOB162HH5k7I3FVbgFSMMYg7dSPBQQ=
+github.com/charmbracelet/x/ansi v0.11.8/go.mod h1:ZNN+3mXny/516oTQPLMPIBeSINvNJJQ8uQXDgbeJxY0=
 github.com/charmbracelet/x/conpty v0.2.0 h1:eKtA2hm34qNfgJCDp/M6Dc0gLy7e07YEK4qAdNGOvVY=
 github.com/charmbracelet/x/conpty v0.2.0/go.mod h1:fexgUnVrZgw8scD49f6VSi0Ggj9GWYIrpedRthAwW/8=
 github.com/charmbracelet/x/exp/golden v0.0.0-20250806222409-83e3a29d542f h1:pk6gmGpCE7F3FcjaOEKYriCvpmIN4+6OS/RD0vm4uIA=