fix: Skip adding entries in external dirs instead of erroring

internal/chezmoi/sourcestate.go

@@ -313,20 +313,21 @@ type ReplaceFunc func(targetRelPath RelPath, newSourceStateEntry, oldSourceState
 
 // AddOptions are options to SourceState.Add.
 type AddOptions struct {
-	AutoTemplate      bool             // Automatically create templates, if possible.
-	Create            bool             // Add create_ entries instead of normal entries.
-	Encrypt           bool             // Encrypt files.
-	EncryptedSuffix   string           // Suffix for encrypted files.
-	Exact             bool             // Add the exact_ attribute to added directories.
-	Filter            *EntryTypeFilter // Entry type filter.
-	OnIgnoreFunc      func(RelPath)    // Function to call when a target is ignored.
-	PreAddFunc        PreAddFunc       // Function to be called before a source entry is added.
-	ConfigFileAbsPath AbsPath          // Path to config file.
-	ProtectedAbsPaths []AbsPath        // Paths that must not be added.
-	RemoveDir         RelPath          // Directory to remove before adding.
-	ReplaceFunc       ReplaceFunc      // Function to be called before a source entry is replaced.
-	Template          bool             // Add the .tmpl attribute to added files.
-	TemplateSymlinks  bool             // Add symlinks with targets in the source or home directories as templates.
+	AutoTemplate      bool                 // Automatically create templates, if possible.
+	Create            bool                 // Add create_ entries instead of normal entries.
+	Encrypt           bool                 // Encrypt files.
+	EncryptedSuffix   string               // Suffix for encrypted files.
+	Errorf            func(string, ...any) // Function to print errors.
+	Exact             bool                 // Add the exact_ attribute to added directories.
+	Filter            *EntryTypeFilter     // Entry type filter.
+	OnIgnoreFunc      func(RelPath)        // Function to call when a target is ignored.
+	PreAddFunc        PreAddFunc           // Function to be called before a source entry is added.
+	ConfigFileAbsPath AbsPath              // Path to config file.
+	ProtectedAbsPaths []AbsPath            // Paths that must not be added.
+	RemoveDir         RelPath              // Directory to remove before adding.
+	ReplaceFunc       ReplaceFunc          // Function to be called before a source entry is replaced.
+	Template          bool                 // Add the .tmpl attribute to added files.
+	TemplateSymlinks  bool                 // Add symlinks with targets in the source or home directories as templates.
 }
 
 // Add adds destAbsPathInfos to s.
@@ -389,11 +390,19 @@ func (s *SourceState) Add(
 	newSourceStateEntries := make(map[SourceRelPath]SourceStateEntry)
 	newSourceStateEntriesByTargetRelPath := make(map[RelPath]SourceStateEntry)
 	nonEmptyDirs := make(map[SourceRelPath]struct{})
+	externalDirRelPaths := make(map[RelPath]struct{})
 	dirRenames := make(map[AbsPath]AbsPath)
 DEST_ABS_PATH:
 	for _, destAbsPath := range destAbsPaths {
 		targetRelPath := destAbsPath.MustTrimDirPrefix(s.destDirAbsPath)
 
+		// Skip any entries in known external dirs.
+		for externalDir := range externalDirRelPaths {
+			if targetRelPath.HasDirPrefix(externalDir) {
+				continue DEST_ABS_PATH
+			}
+		}
+
 		// Find the target's parent directory in the source state.
 		var parentSourceRelPath SourceRelPath
 		if targetParentRelPath := targetRelPath.Dir(); targetParentRelPath == DotRelPath {
@@ -418,7 +427,13 @@ DEST_ABS_PATH:
 				case i != len(nodes)-1 && !ok:
 					panic(fmt.Errorf("nodes[%d]: unexpected non-terminal source state entry, got %T", i, node.sourceStateEntry))
 				case ok && sourceStateDir.Attr.External:
-					return fmt.Errorf("%s: cannot add entry in external_ directory", destAbsPath)
+					targetRelPathComponents := targetRelPath.SplitAll()
+					externalDirRelPath := EmptyRelPath.Join(targetRelPathComponents[:i]...)
+					externalDirRelPaths[externalDirRelPath] = struct{}{}
+					if options.Errorf != nil {
+						options.Errorf("%s: skipping entries in external_ directory\n", externalDirRelPath)
+					}
+					continue DEST_ABS_PATH
 				}
 			}
 			parentSourceRelPath = nodes[len(nodes)-1].sourceStateEntry.SourceRelPath()

internal/cmd/addcmd.go

@@ -187,6 +187,7 @@ func (c *Config) runAddCmd(cmd *cobra.Command, args []string, sourceState *chezm
 			Encrypt:           c.Add.Encrypt,
 			EncryptedSuffix:   c.encryption.EncryptedSuffix(),
 			Exact:             c.Add.exact,
+			Errorf:            c.errorf,
 			Filter:            c.Add.filter,
 			OnIgnoreFunc:      c.defaultOnIgnoreFunc,
 			PreAddFunc:        c.defaultPreAddFunc,

internal/cmd/importcmd.go

@@ -88,6 +88,7 @@ func (c *Config) runImportCmd(cmd *cobra.Command, args []string, sourceState *ch
 		archiveReaderSystem,
 		archiveReaderSystem.FileInfos(),
 		&chezmoi.AddOptions{
+			Errorf:    c.errorf,
 			Exact:     c._import.exact,
 			Filter:    c._import.filter,
 			RemoveDir: removeDir,

internal/cmd/mackupcmd_darwin.go

@@ -109,6 +109,7 @@ func (c *Config) runMackupAddCmd(cmd *cobra.Command, args []string, sourceState
 		c.destSystem,
 		destAbsPathInfos,
 		&chezmoi.AddOptions{
+			Errorf:       c.errorf,
 			Filter:       chezmoi.NewEntryTypeFilter(chezmoi.EntryTypesAll, chezmoi.EntryTypesNone),
 			OnIgnoreFunc: c.defaultOnIgnoreFunc,
 			PreAddFunc:   c.defaultPreAddFunc,

internal/cmd/readdcmd.go

@@ -146,6 +146,7 @@ TARGET_REL_PATH:
 		if err := sourceState.Add(c.sourceSystem, c.persistentState, c.destSystem, destAbsPathInfos, &chezmoi.AddOptions{
 			Encrypt:         sourceStateFile.Attr.Encrypted,
 			EncryptedSuffix: c.encryption.EncryptedSuffix(),
+			Errorf:          c.errorf,
 			Filter:          c.reAdd.filter,
 		}); err != nil {
 			return err

internal/cmd/testdata/scripts/issue3525.txtar

@@ -1,10 +1,10 @@
 # test that chezmoi add does not add files in external_ directories
-! exec chezmoi add $HOME${/}.external/file
-stderr 'cannot add entry in external_ directory'
+exec chezmoi add $HOME${/}.external/file
+stderr '.external: skipping entries in external_ directory'
 
 # test that chezmoi add does not add files in subdirectories of external_ directories
-! exec chezmoi add $HOME${/}.external/dir/file
-stderr 'cannot add entry in external_ directory'
+exec chezmoi add $HOME${/}.external/dir/file
+stderr '.external: skipping entries in external_ directory'
 
 -- home/user/.external/dir/file --
 # contents of .external/dir/file

internal/cmd/testdata/scripts/issue3652.txtar

@@ -0,0 +1,12 @@
+# test that chezmoi add skips files in external_ directories
+exec chezmoi apply
+exists $HOME/.dir/submodule/.git/.keep
+exec chezmoi add $HOME${/}.dir
+stderr '.dir/submodule: skipping entries in external_ directory'
+cmp $CHEZMOISOURCEDIR/dot_dir/file golden/file
+
+-- golden/file --
+# contents of file
+-- home/user/.dir/file --
+# contents of file
+-- home/user/.local/share/chezmoi/dot_dir/external_submodule/.git/.keep --