Resque: adress family not supported

I've been using resque wit redis quite happily for some time now, and everything was great. except that it stopped working a few days ago, after some non-related change in the code.

I get the following error when trying to start a worker:

web_1 | Errno::EAFNOSUPPORT: Address family not supported by protocol - socket(2)

I've tried reverting to an earlier point in time in the git history but that doesn't fix the problem... i've also checked the config multiple times.

However, i'm not super familiar with the inner workings of redis nor resque. Any idea what's going wrong? how can I ge more info on my problem?

Here's the full trace:

web_1    | rake aborted!
web_1    | Errno::EAFNOSUPPORT: Address family not supported by protocol - socket(2)
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/connection/ruby.rb:39:in `initialize'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/connection/ruby.rb:39:in `initialize'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/connection/ruby.rb:195:in `new'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/connection/ruby.rb:195:in `connect_addrinfo'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/connection/ruby.rb:239:in `block in connect'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/connection/ruby.rb:237:in `each'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/connection/ruby.rb:237:in `each_with_index'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/connection/ruby.rb:237:in `connect'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/connection/ruby.rb:313:in `connect'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/client.rb:336:in `establish_connection'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/client.rb:101:in `block in connect'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/client.rb:293:in `with_reconnect'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/client.rb:100:in `connect'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/client.rb:364:in `ensure_connected'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/client.rb:221:in `block in process'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/client.rb:306:in `logging'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/client.rb:220:in `process'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis/client.rb:120:in `call'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis.rb:504:in `block in exists'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis.rb:58:in `block in synchronize'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis.rb:58:in `synchronize'
web_1    | /usr/local/bundle/gems/redis-3.3.5/lib/redis.rb:503:in `exists'
web_1    | /usr/local/bundle/gems/redis-namespace-1.6.0/lib/redis/namespace.rb:442:in `call_with_namespace'
web_1    | /usr/local/bundle/gems/redis-namespace-1.6.0/lib/redis/namespace.rb:328:in `method_missing'
web_1    | /usr/local/bundle/gems/resque-scheduler-3.1.0/lib/resque/scheduler/scheduling_extensions.rb:55:in `schedule='
web_1    | /app/lib/tasks/resque.rake:28:in `block (2 levels) in <top (required)>'
web_1    | /usr/local/bundle/gems/rake-12.3.2/exe/rake:27:in `<top (required)>'
web_1    | Tasks: TOP => resque:scheduler => resque:setup_schedule
web_1    | (See full trace by running task with --trace)

Thanks in advance for your help!