I can see test failures at test-package_revision_list.R:

== Failed tests ================================================================
-- Error (test-package_revision_list.R:10:3): package_revision_list gives back expected class types --
Error: Error: 400 - Bad Request
Error: Error: R CMD check found ERRORs
Execution halted
  "Bad request - Action name not known: package_revision_list"
Backtrace:
    x
 1. \-ckanr::package_revision_list(.a[[1]]$id, url = u) test-package_revision_list.R:10:2
 2.   \-ckanr:::ckan_GET(...)
 3.     \-ckanr:::ckan_VERB(...)
 4.       \-ckanr:::err_handler(res)
-- Error (test-package_revision_list.R:17:3): package_revision_list works giving back json output --

I didn't touch that code, and the logs of the recent (failed) CI tests have expired. Doesn't look like my changes have introduced this breakage, but happy to attempt a fix if I could get working test creds.

thanks for doing this so quickly @florianm - and sorry for the delay in looking at it!!

Re: test credentials, I've been using https://beta.ckan.org/, since registration to demo.ckan.org has been disabled (ckan/ckan#5788 (comment)) - sounds like we might want to switch the documentation over to using the beta site instead of the demo site! But anyways, if you want to test things then you should be able to register at https://beta.ckan.org/ and set up a key there, and then test with that.