Hello.
There's a typo in the doc/diffutils.texi file:
In the example of the Detailed Context node, it reads:
*** @var{from-file} @var{from-file-modification-time}
--- @var{to-file} @var{to-file-modification time}
A "-" is missing in the second line. It should be:
--- @var{to-file} @var{to-file-modification-time}
Best regards,
Mauro.