Elixir GenStage crashes when receiving demand from Ergo

[okkdev]

Describe the bug
Elixir GenStage crashes when receiving demand from Ergo.
Error:

[error] GenServer Producer terminating
** (FunctionClauseError) no function clause matching in GenStage.maybe_producer_cancel/2

To Reproduce
I made a small repo with the reproduction steps:
https://github.com/okkdev/ergo_elixir_genstage_issue

Expected behavior
Have the Elixir Producer handle the demand and Ergo do the work.

Environment (please complete the following information):

• Arch: arm64
• OS: macOS
• Framework Version v1.999.210
• Number of CPU: 10

[halturin]

Thanks for the detailed report. I'll take a look

[halturin]

fixed in 2.1.1