[tex-live] Having a .fmt for different engines

[Thomas Esser]

Jonathan Kew schrieb:
> We've discussed a possible fmtutil patch (and texmf.cnf update), but 
> it's not clear to me that a decision has been made at this point.

I have not been active in following any discussions for a few months now.
In todays discussion, I see that several people have remembered that I
am all against having duplicates in texmf trees. We can't really go without
them (e.g. language.dat), but the use of duplicates should only be done
for a very good reason.

kpathsea has a few tricks that allows us to do this to some extend. But,
it all only works if the setup is 100% right and it fails as soon as
something is slightly wrong. A user setting
	TEXFORMATS=/my/special/dir:$TEXMF/web2c//
will mess it up as well as a user who manually puts mpost's file into
texmf/web2c/mpost instead of texmf/web2c/metapost. And, don't forget that
users tend to have "old" trees which they for sure want to reuse with
the next TeX Live.

Having different filenames if much easier to understand for users.

How about changing all tools to generate
	$format-$engine.fmt
(or even $format-progname.fmt)
and patch kpathsea to make it search for
	$format-$progname.fmt $format-$engine.fmt $format.fmt?
(in that order)?

That would fix the "we want to have one format with different engines"
problems.

Please, consider all this as just my personal opinion. I don't want to
give preasure to one solution or another.

Thomas

PS: I even don't have the current TL sources here. Is there a short
   guide about downloading / submitting updates?