running gitlab-triage with --all-projects and no source or source-id results in argument error

It seems there's some conflict between source/source-id (or their defaults?) and the all-projects option

$ gitlab-triage -t ${GITLAB_TOKEN} --dry-run --all-projects -d
Traceback (most recent call last):
	8: from /home/nate/.local/bin/gitlab-triage:23:in `<main>'
	7: from /home/nate/.local/bin/gitlab-triage:23:in `load'
	6: from /home/nate/.gem/ruby/2.5.0/gems/gitlab-triage-1.15.0/bin/gitlab-triage:10:in `<top (required)>'
	5: from /usr/lib/ruby/2.5.0/set.rb:338:in `each'
	4: from /usr/lib/ruby/2.5.0/set.rb:338:in `each_key'
	3: from /home/nate/.gem/ruby/2.5.0/gems/gitlab-triage-1.15.0/bin/gitlab-triage:14:in `block in <top (required)>'
	2: from /home/nate/.gem/ruby/2.5.0/gems/gitlab-triage-1.15.0/bin/gitlab-triage:14:in `new'
	1: from /home/nate/.gem/ruby/2.5.0/gems/gitlab-triage-1.15.0/lib/gitlab/triage/engine.rb:52:in `initialize'
/home/nate/.gem/ruby/2.5.0/gems/gitlab-triage-1.15.0/lib/gitlab/triage/engine.rb:97:in `assert_all!': --all-projects option cannot be used in conjunction with --source and --source-id option! (ArgumentError)

Let me know if any further detail is needed.