zstd and Mercurial packaging

[Danek Duvall]

Gregory Szorc wrote:

> Mercurial 4.1 has native support for zstd, a relatively new (and awesome)
> compression library.
> 
> For reasons explained in the commit messages at
> https://www.mercurial-scm.org/repo/hg/rev/2e484bdea8c4 and
> https://www.mercurial-scm.org/repo/hg/rev/b86a448a2965, the zstd library
> and python-zstandard Python bindings to it are now vendored in the
> Mercurial repository and their sources will be distributed with the
> Mercurial 4.1 release.
> 
> I know this has implications for packagers, some of whom have policies that
> prefer "unbundling" dependencies.
> 
> zstd has some compelling performance advantages over zlib (the current
> default compression engine). So having downstream Mercurial distributions
> support zstd out of the box should be in the best interest of Mercurial
> users.
> 
> I'm sending this email to reach out to packagers so we have time to address
> packaging concerns around zstd. I'm willing to make upstream changes to
> both Mercurial and python-zstandard to ease packaging issues. Please read
> the aforementioned commit messages to understand the vendoring decision and
> then let me know if there is anything I can do to make your life easier.

Coming from a distributor that prefers to unvendor things as much as
possible, the rationale here seems perfectly reasonable to me.  Thanks
for reaching out on this one.

Danek