bloom releases dropped packages which still have branches in the release repository.

[nuclearsandwich]

I'll leave my ros_ign-release fork up as an example, but bloom uses existing branch names to find which packages to generate for, which means that packages dropped from a distribution are still released:

bloom/bloom/generators/debian/generator.py

Lines 674 to 684 in b42a1dd

	for branch in self.branches:
	package = get_package_from_branch(branch)
	if package is None:
	# This is an ignored package
	continue
	self.packages[package.name] = package
	self.names.append(package.name)
	args = self.generate_branching_arguments(package, branch)
	# First branch is debian/[<rosdistro>/]<package>
	self.debian_branches.append(args[0][0])
	self.branch_args.extend(args)

The way to mitigate this is to add a $TRACK.ignored file and ignore the defunct packages. Placing a COLCON_IGNORE or CATKIN_IGNORE in the upstream repo instead of removing the directory completely may also work.