This update for rubygem-rack fixes the following issues:
{ "binaries": [ { "ruby2.5-rubygem-rack": "2.0.8-150000.3.21.2" } ] }
{ "binaries": [ { "ruby2.5-rubygem-rack": "2.0.8-150000.3.21.2", "ruby2.5-rubygem-rack-doc": "2.0.8-150000.3.21.2", "ruby2.5-rubygem-rack-testsuite": "2.0.8-150000.3.21.2" } ] }