fix: prune fails to remove versions containing read-only dirs (#226)

os.RemoveAll returns 'permission denied' and leaves the directory in
place when a version tree contains read-only directories (e.g. Go
module-cache style trees with mode 0555). cleanVersionDir swallowed the
error, so prune/uninstall reported success while every version stayed on
disk and a second prune produced identical output.

Add utils.RemoveAll, which makes directories writable before removing,
return the error from cleanVersionDir, and report a real failure from
Uninstall instead of a false success.

Author: juev

gobrew.go

@@ -312,7 +312,10 @@ func (gb *GoBrew) Uninstall(version string) {
 		color.Errorf("[Error] Version: %s you are trying to remove is your current version. Please use a different version first before uninstalling the current version\n", version)
 		os.Exit(1)
 	}
-	gb.cleanVersionDir(version)
+	if err := gb.cleanVersionDir(version); err != nil {
+		color.Errorf("==> [Error] Failed to uninstall version: %s: %s\n", version, err)
+		return
+	}
 	color.Successf("==> [Success] Version: %s uninstalled\n", version)
 }
 

gobrew_test.go

@@ -154,6 +154,31 @@ func TestPrune(t *testing.T) {
 	t.Log("test finished")
 }
 
+// TestPruneReadOnlyDir reproduces issue #226: a read-only directory inside an
+// installed version (e.g. a Go module-cache style tree with mode 0555) made
+// os.RemoveAll fail with "permission denied", so prune reported success while
+// the version stayed on disk.
+func TestPruneReadOnlyDir(t *testing.T) {
+	t.Parallel()
+	ts := httptest.NewServer(http.FileServer(http.Dir("testdata")))
+	defer ts.Close()
+	gb := setupGobrew(t, ts)
+	gb.Install("1.20")
+	gb.Install("1.19")
+	gb.Use("1.19")
+
+	// Inject a read-only directory holding a read-only file into version 1.20.
+	roDir := filepath.Join(gb.getVersionDir("1.20"), "go", "readonly")
+	assert.NoError(t, os.MkdirAll(roDir, 0o755))
+	assert.NoError(t, os.WriteFile(filepath.Join(roDir, "f"), []byte("x"), 0o600))
+	assert.NoError(t, os.Chmod(roDir, 0o555))
+
+	gb.Prune()
+	assert.Equal(t, false, gb.existsVersion("1.20"))
+	assert.Equal(t, true, gb.existsVersion("1.19"))
+	t.Log("test finished")
+}
+
 func TestGoBrew_CurrentVersion(t *testing.T) {
 	t.Parallel()
 	ts := httptest.NewServer(http.FileServer(http.Dir("testdata")))

helpers.go

@@ -153,8 +153,8 @@ func (gb *GoBrew) existsVersion(version string) bool {
 	return err == nil
 }
 
-func (gb *GoBrew) cleanVersionDir(version string) {
-	_ = os.RemoveAll(gb.getVersionDir(version))
+func (gb *GoBrew) cleanVersionDir(version string) error {
+	return utils.RemoveAll(gb.getVersionDir(version))
 }
 
 func (gb *GoBrew) cleanDownloadsDir() {
@@ -263,7 +263,7 @@ func (gb *GoBrew) downloadAndExtract(version string) {
 	err = gb.extract(srcTar, dstDir)
 	if err != nil {
 		// clean up dir
-		gb.cleanVersionDir(version)
+		_ = gb.cleanVersionDir(version)
 		color.Errorln("==> [Info] Extract failed:", err)
 		os.Exit(1)
 	}

utils/utils.go

@@ -3,9 +3,11 @@ package utils
 import (
 	"fmt"
 	"io"
+	"io/fs"
 	"net/http"
 	"os"
 	"path"
+	"path/filepath"
 
 	"github.com/gookit/color"
 	"github.com/schollz/progressbar/v3"
@@ -52,6 +54,27 @@ func DownloadWithProgress(url string, tarName string, destFolder string) (err er
 	return nil
 }
 
+// RemoveAll removes path and all its children, making any read-only
+// directories writable first. A plain os.RemoveAll fails with
+// "permission denied" when the tree contains read-only directories
+// (e.g. Go module-cache style trees with mode 0555), leaving the
+// directory in place. Making directories writable before removal avoids
+// silently failing to delete an installed Go version.
+func RemoveAll(path string) error {
+	_ = filepath.WalkDir(path, func(p string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return nil
+		}
+		// WalkDir does not follow symlinks and d.IsDir() is false for
+		// symlinked dirs, so p stays within gobrew's version tree.
+		if d.IsDir() {
+			_ = os.Chmod(p, 0o755) //nolint:gosec // path is confined to the walked tree
+		}
+		return nil
+	})
+	return os.RemoveAll(path)
+}
+
 func CheckError(err error, format string) {
 	if err != nil {
 		color.Errorf(format+": %s", err)