temp: add Windows reproduction for export-dir on illegal notebook name

NEXT_CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Notable Changes
 
 ### CLI
+* `workspace export-dir` no longer aborts when a workspace object's name is not a legal local filename (e.g. a notebook named `New Notebook 2026-05-04 13:54:24` whose `:` is illegal on Windows). Such files are now skipped with a warning and the export completes ([#5171](https://github.com/databricks/cli/issues/5171)).
 
 ### Bundles
 * `bundle run` now prints the modern job run URL (`/jobs/<id>/runs/<id>`) so that non-admin users permitted to view the run are taken to the run instead of the workspace homepage.

acceptance/cmd/workspace/export-dir-illegal-filename/notebook.py

@@ -0,0 +1,2 @@
+# Databricks notebook source
+print("hello")

acceptance/cmd/workspace/export-dir-illegal-filename/output.txt

@@ -0,0 +1,5 @@
+
+>>> [CLI] workspace export-dir /test-dir [TEST_TMP_DIR]/export
+Exporting files from /test-dir
+/test-dir/New Notebook [TIMESTAMP] (skipped; invalid name for local file system)
+Export complete

acceptance/cmd/workspace/export-dir-illegal-filename/script

@@ -0,0 +1,7 @@
+$CLI workspace import "/test-dir/New Notebook 2026-05-04 13:54:24.py" --file notebook.py --format AUTO --language PYTHON
+
+mkdir -p "$TEST_TMP_DIR/export"
+
+# On Windows the notebook name contains ':' which is illegal in a local filename.
+# export-dir should skip it with a warning and still complete (databricks/cli#5171).
+trace $CLI workspace export-dir /test-dir "$TEST_TMP_DIR/export"

acceptance/cmd/workspace/export-dir-illegal-filename/test.toml

@@ -0,0 +1,28 @@
+Local = true
+Cloud = false
+
+# This reproduces databricks/cli#5171, which only manifests on Windows: a ':' in
+# the notebook name is a legal filename character on Linux/macOS but illegal on
+# Windows, so os.Create rejects the local target path there.
+[GOOS]
+darwin = false
+linux = false
+windows = true
+
+[Env]
+MSYS_NO_PATHCONV = "1"
+
+[[Server]]
+Pattern = "GET /api/2.0/workspace/list"
+Response.Body = '''
+{
+  "objects": [
+    {
+      "path": "/test-dir/New Notebook 2026-05-04 13:54:24",
+      "object_type": "NOTEBOOK",
+      "language": "PYTHON",
+      "object_id": 123
+    }
+  ]
+}
+'''

cmd/workspace/workspace/export_dir.go

@@ -125,6 +125,13 @@ func (opts *exportDirOptions) callback(ctx context.Context, workspaceFiler filer
 		// create the file
 		f, err := os.Create(targetPath)
 		if err != nil {
+			// A workspace name can be illegal as a local filename (e.g. a ':'
+			// in "New Notebook 2026-05-04 13:54:24" on Windows). Skip those with
+			// a warning rather than aborting the whole export (#5171).
+			if isInvalidLocalNameError(err) {
+				cmdio.LogString(ctx, sourcePath+" (skipped; invalid name for local file system)")
+				return nil
+			}
 			return err
 		}
 		defer f.Close()

cmd/workspace/workspace/export_dir_other.go

@@ -0,0 +1,11 @@
+//go:build !windows
+
+package workspace
+
+// isInvalidLocalNameError reports whether err means the workspace object could
+// not be written because its name is not a legal filename on the local OS. On
+// non-Windows platforms the only bytes illegal in a filename are '/' and NUL,
+// neither of which can appear in a workspace object name, so this never fires.
+func isInvalidLocalNameError(err error) bool {
+	return false
+}

cmd/workspace/workspace/export_dir_windows.go

@@ -0,0 +1,21 @@
+//go:build windows
+
+package workspace
+
+import (
+	"errors"
+	"syscall"
+)
+
+// errorInvalidName is the Windows ERROR_INVALID_NAME code. The file APIs return
+// it when a path contains characters that are illegal in a local filename, such
+// as the ':' in a notebook named "New Notebook 2026-05-04 13:54:24". It is not
+// declared in the standard syscall package, so we use the well-known code.
+// https://learn.microsoft.com/en-us/windows/win32/debug/system-error-codes--0-499-
+const errorInvalidName = syscall.Errno(0x7b)
+
+// isInvalidLocalNameError reports whether err means the workspace object could
+// not be written because its name is not a legal filename on the local OS.
+func isInvalidLocalNameError(err error) bool {
+	return errors.Is(err, errorInvalidName)
+}

cmd/workspace/workspace/export_dir_windows_test.go

@@ -0,0 +1,56 @@
+//go:build windows
+
+package workspace
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"syscall"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// The narrow contract: only the Windows "invalid file name" error is treated as
+// skippable. Genuine failures (permission, missing path, anything else) must not
+// be swallowed, otherwise export-dir would silently drop files on real errors.
+func TestIsInvalidLocalNameError(t *testing.T) {
+	tests := []struct {
+		name string
+		err  error
+		want bool
+	}{
+		{
+			name: "invalid name wrapped in PathError",
+			err:  &os.PathError{Op: "open", Path: `C:\tmp\New Notebook 13:54:24.py`, Err: syscall.Errno(0x7b)},
+			want: true,
+		},
+		{
+			name: "permission denied is not skipped",
+			err:  fs.ErrPermission,
+			want: false,
+		},
+		{
+			name: "not exist is not skipped",
+			err:  fs.ErrNotExist,
+			want: false,
+		},
+		{
+			name: "generic error is not skipped",
+			err:  errors.New("boom"),
+			want: false,
+		},
+		{
+			name: "nil is not skipped",
+			err:  nil,
+			want: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.want, isInvalidLocalNameError(tt.err))
+		})
+	}
+}