zkg 2.10.0 is out, with the following updates:
The Zeek master branch now uses this version.
A related heads-up: with the upcoming Zeek 4.1 release we'll modernize the Zeek package source (https://github.com/zeek/packages) by switching its index files from bro-pkg.index to zkg.index. This change is transparent unless you're still using dated versions of zkg (bro-pkg prior to 2.0.0) -- those versions will no longer "see" packages in the package source at that point (and already only see a fraction today). zkg itself continues to support Bro-era metadata files.