[tz] [PROPOSED PATCH 2/2] Use lz format for new tarball

[Paul Eggert]

Deborah Goldsmith wrote:

> It’s going to require changing (multiple) existing workflows that are working just fine.

It sounds like you're not alone with these concerns. OK, then let's keep 
supporting the existing distribution format indefinitely. Plus, it sounds like 
we should stick with the current set of files in the format, rather than add the 
(somewhat large) .tzs file to the data tarball.

Instead, I plan to call the new-format tarball "experimental" for now. This is 
probably just as well, as that should give more freedom to try other things out 
too. The experimental tarball can contain the .tzs file without disrupting the 
traditional format. And if this experiment doesn't work out, we can stop 
distributing this new-format tarball in future releases, or change the new format.

To do all this, I plan to send out a proposed patchset shortly.

As for choice of compression format, the new format is intended for developers, 
not for end-user devices. So I'm not concerned whether some embedded platforms 
lack support for .lz or for .xz or whatever. Developers can easily get support 
for all the formats discussed, and we might as well pick a format that 
compresses well. It is an experiment after all.