microsoft/typescript-go · error

could not get file information

Error message

could not get file information

What it means

Static error returned synchronously from WatchDirectory on Windows when GetFileInformationByHandle fails immediately after CreateFile succeeded while opening the watched directory in newWindowsSubscription. The handle is closed and the sentinel is returned as-is (no errno attached), so the caller sees exactly 'could not get file information'. It is rare by construction: the open worked but the metadata query failed.

Source

Thrown at internal/fswatch/windows.go:106

//  3. Walk the FILE_NOTIFY_INFORMATION linked list:
//     - FILE_ACTION_ADDED / RENAMED_NEW_NAME  → events.create (→ EventUpdate)
//     - FILE_ACTION_MODIFIED                  → events.update (→ EventUpdate)
//     - FILE_ACTION_REMOVED / RENAMED_OLD_NAME → events.remove + tree.remove
//  4. Call dirWatch.notify() to trigger the debouncer.
//
// Error recovery:
//   - ERROR_OPERATION_ABORTED → normal shutdown (CancelIoEx was called).
//   - ERROR_INVALID_PARAMETER → shrink buffer to 64 KB (network share limit).
//   - ERROR_NOTIFY_ENUM_DIR  → ErrOverflow (too many changes queued).
//   - ERROR_ACCESS_DENIED    → check if the watched dir was deleted.
//
// Shutdown:
//   close(stopCh) → CancelIoEx cancels in-flight IO → run() goroutine
//   exits → deferred CloseHandle closes the directory handle → doneCh closed.
// ---------------------------------------------------------------------------

var (
	errGetFileInfo         = errors.New("could not get file information")
	errReadChanges         = errors.New("failed to read changes")
	errGetOverlappedResult = errors.New("GetOverlappedResult failed")
	errUnknown             = errors.New("unknown error")
)

const (
	defaultBufSize = 1024 * 1024
	networkBufSize = 64 * 1024

	notifyChangeFilter = windows.FILE_NOTIFY_CHANGE_FILE_NAME |
		windows.FILE_NOTIFY_CHANGE_DIR_NAME |
		windows.FILE_NOTIFY_CHANGE_SIZE |
		windows.FILE_NOTIFY_CHANGE_LAST_WRITE
)

// windowsBackend.
type windowsBackend struct {
	watcherBase

View on GitHub (pinned to 1bcfa18d79)

Solutions

1. Retry WatchDirectory after a short backoff; transient handle failures usually clear on the next attempt
2. Verify with os.Stat that the path is still a readable directory, then re-subscribe
3. For network shares, stabilize the connection or watch a local mirror
4. If it persists, trace OS-level failures with Process Monitor to find the interfering driver

if _, err := os.Stat(dir); err != nil {
    return err // wait for the directory/share before subscribing
}

watch, err := w.WatchDirectory(dir, cb)
if err != nil && err.Error() == "could not get file information" {
    // transient: retry with backoff
    time.Sleep(250 * time.Millisecond)
    watch, err = w.WatchDirectory(dir, cb)
}

When it happens

Trigger: The directory handle is invalidated between CreateFile and the metadata call: the network share dropped, the device was removed, or a filter driver interfered. Filesystem corruption or driver bugs can also produce it.

Common situations: UNC network paths on flaky links during subscribe. Removable media ejected at that exact moment. Antivirus or ERM filter drivers that quarantine the directory between the two calls.

Related errors

• GetOverlappedResult failed
• error opening directory: %w
• invalid handle: %w
• Child process exited with code ${this.child.exitCode} before
• SyncRpcChannel: timed out connecting to named pipe

AI-assisted analysis of microsoft/typescript-go@1bcfa18d79 (2026-08-16). Data as JSON: /api/errors/2b260dc7510dc609. Report an issue: GitHub.