Include dot file name in dot file user error.
Include dot file name in dot file user error.

Log dotfiles like files with invalid characters, to make it easier to
see from the log message what the problem is.

dag-erling/tsdfx,petterreinholdtsen/tsdfx,petterreinholdtsen/tsdfx,petterreinholdtsen/tsdfx,dag-erling/tsdfx,dag-erling/tsdfx