REPL : pureFunctions and captureChecking fail with "language import only allowed at toplevel"

[rjolly]

Compiler version

3.2.2-RC1-bin-SNAPSHOT-git-292e56f

Minimized code

scala> import language.experimental.captureChecking

Output

-- Error: ----------------------------------------------------------------------
1 |import language.experimental.captureChecking
  |                             ^^^^^^^^^^^^^^^
  |                      this language import is only allowed at the toplevel

Expectation

Should work. See f2c1b24

[anatoliykmetyuk]

This issue was picked for the Issue Spree No. 23 of 08 November 2022 which takes place in a week from now. @rjolly, @mbovel will be working on it. If you have any insight into the issue or guidance on how to fix it, please leave it here.

[dwijnand]

Working on imports and the REPL is hard. I encountered this reality while working on PR #14021 and there's related history that touches on things like withRootImports and the CollectTopLevelImports phase.

[scala-center-bot]

This issue was picked for the Issue Spree No. 25 of 24 January 2023 which takes place in a week from now. @rjolly, @TheElectronWill will be working on it. If you have any insight into the issue or guidance on how to fix it, please leave it here.

[mbovel]

#16304 is a work-in-progress PR for this issue, see comments there.