mlr3 code failing in Geocomputation with R book

[Robinlovelace]

We're seeing new error messages in our CI workflows that seem to be related to {mlr3}. I'm not sure what the exact cause is, @jannes-m plans to look into it, but I wanted to let the developer team know as I guess it's affecting others. See below links and some investigations by us that I hope is usefull:

• The section that is failing with the latest version (rendered with previous package versions, the failing code blocks can be found at the end of this section, specifically in the code chunks around autotuner_rf$train(task): https://r.geocompx.org/eco#mlr3-building-blocks

Should we add , store_backends = TRUE during model fitting as suggested there?

! The backend of Task 'mongon' has been removed. Set `store_backends` to `TRUE` during model fitting to conserve it.
Backtrace:
  1. base::eval(...)
 27. mlr3 (local) `<fn>`()
 28. mlr3:::.__Task__groups(...)
 29. mlr3:::assert_has_backend(self)
 30. mlr3misc::stopf(...)
Warning messages:
1: In warn_deprecated("Task$data_formats") :
  Task$data_formats is deprecated and will be removed in the future.
2: In warn_deprecated("DataBackend$data_formats") :
  DataBackend$data_formats is deprecated and will be removed in the future.
3: In warn_deprecated("Learner$data_formats") :
  Learner$data_formats is deprecated and will be removed in the future.
Quitting from lines 519-520 [15-eco-26] (15-eco.Rmd)

• PR with changes aimed at fixing the issue and some comments: Do not evaluate failing mlr3::lrn chunk (#1111 hotfix) geocompx/geocompr#1117

Apologies for not having a clearer report or more minimal reproducible example (although it is reproducible) and hope this is helpful.

[jannes-m]

I think we can close this, solved via geocompx/geocompr#1124