On 25/3/19 4:34 am, Robin Broda via arch-dev-public wrote:
This change requires a new pacman release, as as of writing this, zstd support is in master but hasn't landed in a release yet.
Which is a complete blocker for quite a period of time.
We need to assume every system has a copy of pacman-5.2+ before we can switch packages to zstd. Otherwise updates can break systems (pacman and all dependencies will need to stay as .xz for a year at least, and we have to hope that partial update does not break anything until a full update is run). Experience switching from .gz to .xz showed system breakage was a fairly regular occurrence.
I would not do this until at least one year, maybe two after pacman-5.2 is released.