scala - Re-run with -feature for details

Question

When I compile scala in play console, I got this:

[warn] there were 1 feature warning(s); re-run with -feature for details
[warn] one warning found

I thought it means compile -feature, but I got this:

[error] Expected ID character
[error] Not a valid command: compile (similar: completions)
[error] Expected project ID
[error] Expected configuration
[error] Expected ':' (if selecting a configuration)
[error] Expected key
[error] Expected '::'
[error] Expected end of input.
[error] compile -feature
[error]     

Then I run play -feature, I got this:

[warn] The `-` command is deprecated in favor of `onFailure` and will be removed in 0.14.0

And play quit.

So how should I do this?

Answer 1

You have to add

scalacOptions += "-feature"

to your build.sbt and execute reload if your sbt console is running (or restart it).

Alternatively if you want to set it only for a single session, while in sbt console.

set scalacOptions += "-feature"

You can write, this setting is applied immediately, no need to reload or restart sbt console.