It seems the “pkgman install” step updates the Haiku package used for the build, and as a result, it needs a reboot to activate the packages. However, the CI script has the reboot step commented out. So, the installed make package in that step never gets activated.
This happens because there was a new commit added to the beta branch since the docker image used to run the build was generated.
Re-enabling the lines to reboot the Haiku VM should work, or, to avoid that, the docker should be updated to the latest version of Haiku from the beta branch. I do not know who built it and how it was done.