[luatex] Why is --progname needed?

[Arthur Reutenauer]

>        It seems like the timestamp is the most useful version
> identification?

  The timestamp is set at compile-time, not commit-time; it has nothing
to do with the state of the source files you're compiling from (you
could be compiling now a binary from LuaTeX revision #1 from 3 years
ago, for that matter).  I'm personally quite happy to have some
information related to the SVN revision number, even if it isn't
perfect.

	Arthur