Ruby 4.x incompatibility due to prometheus-client DirectFileStore

[nbluis]

Hi 👋
I’m reporting an issue related to Ruby 4.x compatibility that affects yabeda-prometheus through its dependency on prometheus-client.

When using Ruby 4.x, prometheus-client fails when DirectFileStore is used, raising a NoMethodError related to CGI.parse.
Since yabeda-prometheus depends on prometheus-client, this also impacts applications using Yabeda with Ruby 4.

The issue has been reported upstream here:
👉 prometheus/client_ruby#329

Environment

Ruby: 4.0.1
yabeda-prometheus: latest
prometheus-client: 4.2.5

Notes

This issue appears to be entirely upstream in prometheus-client, specifically in DirectFileStore.
I’m opening this issue mainly for visibility and tracking, in case you want to pin versions, document the limitation, or follow up once the upstream fix is released.

Thanks! 🙌