Below is a line from our Concourse job that has built a recent alpha package:
make -C rabbitmq-packaging package-rpm-rhel8 PACKAGES_DIR=/tmp/build/80754af9/PACKAGES RABBITMQ_PACKAGING_REPO=/tmp/build/80754af9/rabbitmq-packaging SOURCE_DIST_FILE=/tmp/build/80754af9/source-archive/rabbitmq-server-3.8.17-alpha.11.tar.xz VERSION=3.8.17-alpha.11 RPM_VERSION=3.8.17~alpha.11 SAVE_CHANGELOG=yes SIGNING_KEY=…
I suspect that SAVE_CHANGELOG and SIGNING_KEY are optional. PACKAGES_DIR is where the artefacts will be stored.
So you primarily need:
* A full distribution source tarball, specified as SOURCE_DIST_FILE
* A local rabbitmq/rabbitmq-packaging repo clone at RABBITMQ_PACKAGING_REPO
* A version to use
This implies you have all the build time dependencies [1] installed.
By the way, I'm pretty sure we produce the package on Debian Buster
since that's what our CI jobs use.