hanami server 2.0.3 on Windows 10 fails with "worker mode not supported" error

[pcopissa]

On Windows 10 64bits follow the steps in https://guides.hanamirb.org/v2.0/introduction/getting-started/
That is:

1. Install Ruby 3.2.1 (using RubyInstaller)
2. In a Ruby-enabled cmd prompt, install hanami 2.0.3 via ridk exec get install hanami.
3. In a Ruby-enabled cmd prompt, create a new project via hanami new test. Manually finish the installation with bundle install (to install missing rack-test)
4. In a Ruby-enabled DOS prompt, start webserver (Puma presumably) via bundle exec hanami server
5. In browser, enter URL http://localhost:2300
6. Observed result: The browser displays an error message Connection failed. Furthermore the DOS prompt in step 2 shows: ERROR: worker mode not supported on ruby on this platform
7. Expected result (according to the "Getting started" page): The browser displays Hello from Hanami

[carlosm27]

Could you try to go to the config/puma.rb file and comment on the line workers ENV.fetch("HANAMI_WEB_CONCURRENCY", 2). That works for me.

[timriley]

Thanks for adding this detail, @carlosm27. From the sounds of it, if we just use a single worker by default, we should be OK on Windows?

[carlosm27]

Yes, I just tried on Windows 11. I think it will work also on Windows 10. I got the solution from this issue.