Undefined method 'after' for nil

[jakeonfire]

seeing this error in our error tracker. it appears to be related to a recent change introduced in v1.4.0 (11d197f) and is occurring on

httpx/lib/httpx/connection.rb

Line 907 in 7c21c33

interval = @current_selector.after(timeout, callback)

. we are using faraday with the httpx adapter and the fiber-based falcon (https://github.com/socketry/falcon) as our webserver.

stack trace from version 1.4.1:

NoMethodError: undefined method 'after' for nil (NoMethodError)

        interval = @current_selector.after(timeout, callback)
                                    ^^^^^^
  from httpx/connection.rb:907:in `block in HTTPX::Connection#set_request_timeout'
  from httpx/callbacks.rb:12:in `block in HTTPX::Callbacks#once'
  from httpx/callbacks.rb:19:in `block in HTTPX::Callbacks#emit'
  from httpx/callbacks.rb:19:in `delete_if'
  from httpx/callbacks.rb:19:in `emit'
  from httpx/request.rb:274:in `transition'
  from httpx/connection/http1.rb:335:in `block in HTTPX::Connection::HTTP1#handle'
  from httpx/connection/http1.rb:334:in `catch'
  from httpx/connection/http1.rb:334:in `handle'
  from httpx/connection/http1.rb:98:in `block in HTTPX::Connection::HTTP1#consume'
  from httpx/connection/http1.rb:94:in `each'
  from httpx/connection/http1.rb:94:in `each_with_index'
  from httpx/connection/http1.rb:94:in `consume'
  from httpx/connection.rb:403:in `block (2 levels) in HTTPX::Connection#consume'
  from <internal:kernel>:168:in `loop'
  from httpx/connection.rb:399:in `block in HTTPX::Connection#consume'
  from httpx/connection.rb:397:in `catch'
  from httpx/connection.rb:397:in `consume'
  from httpx/connection.rb:245:in `call'
  from httpx/selector.rb:182:in `select_one'
  from httpx/selector.rb:117:in `select'
  from httpx/selector.rb:37:in `block in HTTPX::Selector#next_tick'
  from httpx/selector.rb:29:in `catch'
  from httpx/selector.rb:29:in `next_tick'
  from httpx/session.rb:320:in `block (2 levels) in HTTPX::Session#receive_requests'
  from httpx/session.rb:320:in `catch'
  from httpx/session.rb:320:in `block in HTTPX::Session#receive_requests'
  from <internal:kernel>:168:in `loop'
  from httpx/session.rb:315:in `receive_requests'
  from httpx/session.rb:290:in `send_requests'
  from httpx/session.rb:106:in `request'
  from httpx/adapters/faraday.rb:282:in `block in Faraday::Adapter::HTTPX#connect_and_request'
  from faraday/adapter.rb:45:in `connection'
  from httpx/adapters/faraday.rb:45:in `connect'
  from httpx/adapters/faraday.rb:277:in `connect_and_request'
  from httpx/adapters/faraday.rb:267:in `call'
  from faraday/follow_redirects/middleware.rb:77:in `perform_with_redirection'
  from faraday/follow_redirects/middleware.rb:65:in `call'
  from faraday/rack_builder.rb:152:in `build_response'
  from faraday/connection.rb:452:in `run_request'
  from faraday/connection.rb:200:in `get'
  [...snip]

also seeing:

NoMethodError: undefined method 'each' for nil (NoMethodError)

        @ios.each { |io| io.rewind }
            ^^^^^
  from multipart/post/composite_read_io.rb:73:in `rewind'
  from faraday/multipart/file_part.rb:83:in `each'
  from faraday/multipart/file_part.rb:83:in `rewind'
  from delegate.rb:87:in `method_missing'
  from httpx/request/body.rb:75:in `rewind'
  from httpx/request.rb:245:in `transition'
  from httpx/plugins/retries.rb:114:in `fetch_response'
  from httpx/session.rb:320:in `block in HTTPX::Session#receive_requests'
  from <internal:kernel>:168:in `loop'
  from httpx/session.rb:315:in `receive_requests'
  from httpx/session.rb:290:in `send_requests'
  from httpx/session.rb:106:in `request'
  from httpx/adapters/faraday.rb:282:in `block in Faraday::Adapter::HTTPX#connect_and_request'
  from faraday/adapter.rb:45:in `connection'
  from httpx/adapters/faraday.rb:45:in `connect'
  from httpx/adapters/faraday.rb:277:in `connect_and_request'
  from httpx/adapters/faraday.rb:267:in `call'
  from faraday/follow_redirects/middleware.rb:77:in `perform_with_redirection'
  from faraday/follow_redirects/middleware.rb:65:in `call'
  from faraday/multipart/middleware.rb:27:in `call'
  from faraday/rack_builder.rb:152:in `build_response'
  from faraday/connection.rb:452:in `run_request'
  from faraday/connection.rb:280:in `post'
  [...snip]

downgrading to 1.3.4 resolves the errors.

[jakeonfire]

might also be worth mentioning we are doing manual, per-host, per-thread faraday connection caching

class Connections
  extend Thread::Local

  def initialize
    @connections = {}
  end

  # @return [Faraday::Connection]
  def get(base_url, request_middleware: nil)
    key = [base_url, request_middleware].join(":")

    @connections[key] ||= Faraday.new(base_url) do |builder|
      # configure connection
    end
  end
end

[HoneyryderChuck]

Hi, thanks for the report.

It's a known bug, already reported here. I'm engaged with the original reporter in the process of identifying the correct fix.

If you want to help out, and as per instructions in the thread at the bottom of the originalissue, run the issue-334 branch on your side, collect logs and send them to me for further analysis, do keep the ticket open if you don't have a gitlab account. Otherwise, please close it as a duplicate.