lima-vm/lima · error

cannot convert %#q to an MSYS-style path: input is not an ab

Error message

cannot convert %#q to an MSYS-style path: input is not an absolute drive-letter path

What it means

The native cygpath fallback only has a well-defined MSYS-style mapping for absolute drive-letter paths ("C:\foo" -> "/c/foo"). If the input path is not absolute (relative path or drive-relative like "C:foo"), conversion would silently produce an unrelated absolute path, so the function rejects it with this error.

Source

Thrown at pkg/fsutil/fsutil_windows.go:53

		return strings.TrimSpace(string(out)), nil
	}
	if !errors.Is(err, exec.ErrNotFound) && !errors.Is(err, fs.ErrNotExist) {
		return "", fmt.Errorf("failed to run %#q on %#q: %#q: %w", cygpathExe, orig, strings.TrimSpace(string(out)), err)
	}

	logrus.WithError(err).Debugf("%#q not found for %#q, attempting native conversion", cygpathExe, orig)

	return windowsSubsystemPathWithoutCygpath(orig)
}

func windowsSubsystemPathWithoutCygpath(orig string) (string, error) {
	// The /c/... form this produces is the MSYS2 and Git-for-Windows
	// convention; stock Cygwin defaults to /cygdrive/c/. Only an absolute
	// drive-letter path ("C:\foo") has a well-defined form here. A
	// drive-relative path ("C:foo") would become an unrelated absolute
	// path, so reject it.
	if !filepath.IsAbs(orig) {
		return "", fmt.Errorf("cannot convert %#q to an MSYS-style path: input is not an absolute drive-letter path", orig)
	}

	// UNC path ("\\server\share\foo") is rejected here.
	if vol := filepath.VolumeName(orig); len(vol) == 2 && vol[1] == ':' {
		// orig[2:] starts with a separator for an absolute drive path
		// (C:\foo, C:/foo); strip it so the result stays canonical.
		tail := strings.TrimPrefix(filepath.ToSlash(orig[2:]), "/")
		converted := "/" + strings.ToLower(vol[:1]) + "/" + tail
		logrus.Debugf("native cygpath fallback: %#q -> %#q", orig, converted)
		return converted, nil
	}

	return "", fmt.Errorf("cannot convert %#q to an MSYS-style path: input is not an absolute drive-letter path", orig)
}

// WindowsSubsystemPathForLinux converts a Windows path to the WSL form of
// the given distro (e.g. C:\Users\jan -> /mnt/c/Users/jan) via wsl.exe.
func WindowsSubsystemPathForLinux(ctx context.Context, orig, distro string) (string, error) {

View on GitHub (pinned to dd909d0973)

Solutions

1. Convert the input to an absolute path before calling: filepath.Abs(orig) resolved against the intended working directory.
2. Ensure the path starts with a drive letter followed by a separator (C:\...).
3. Reject or prompt for absolute paths at the application's input boundary.
4. Prefer installing cygpath (Git for Windows) so the primary conversion path handles more cases — though absoluteness is still required by the fallback.

Example fix

// before
p, err := fsutil.WindowsSubsystemPath(ctx, relPath)
// after
abs, err := filepath.Abs(relPath)
if err != nil { return err }
p, err := fsutil.WindowsSubsystemPath(ctx, abs)

abs, err := filepath.Abs(orig)
if err != nil { return err }
if vol := filepath.VolumeName(abs); len(vol) != 2 || vol[1] != ':' {
    return fmt.Errorf("need an absolute drive-letter path, got %q", orig)
}
orig = abs

func isAbsoluteDriveLetterPath(p string) bool {
    vol := filepath.VolumeName(p)
    return len(vol) == 2 && vol[1] == ':' && len(p) > 2 && (p[2] == '\\' || p[2] == '/')
}

p, err := fsutil.WindowsSubsystemPath(ctx, orig)
if err != nil && strings.Contains(err.Error(), "not an absolute drive-letter path") {
    return fmt.Errorf("%q must be an absolute path like C:\\foo; resolve it against the working directory first", orig)
}

When it happens

Trigger: Calling WindowsSubsystemPath (fallback path, i.e. cygpath.exe missing) with a relative path like "foo\bar", or a drive-relative path like "C:foo\bar" on Windows.

Common situations: Passing a path built from a relative working directory or user-supplied relative input; deriving paths from tools that return drive-relative results; misusing the API which expects fully-qualified Windows paths.

Related errors

• configuration is nil
• field `mountType` must be %#q for QEMU driver on Windows, go
• fsutil: Windows path conversion is not supported on this pla
• failed to run %#q on %#q: %#q: %w
• --condition=boot is only supported on macOS

AI-assisted analysis of lima-vm/lima@dd909d0973 (2026-09-01). Data as JSON: /api/errors/90489de596886d02. Report an issue: GitHub.