Thanks all for this. chezmoi is now available as a snap package, in the beta channel for now, but in stable once I get a few experience reports.
I only hit one bug related to snap: snap sets the XDG_RUNTIME_DIR environment variable to a directory that doesn’t exist, which breaks programs that assume that it already exists (which is pretty much of them that use it). I added a work-around in chezmoi for this, as this seems to be a long-term issue with snap.
Thanks again to everyone who made this happen: @bashfulrobot @jdstrand @popey.