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JLine version is outdated
Dotty is still on 3.19.0, from way back in 2021.
(Scala 2.13.13 is on 3.24.1, and we'll very likely move to 3.25.1 in 2.13.14.)
Why is the upgrade desirable? No specific killer reason that I'm aware of, but the JLine folks are always fixing bugs, especially for Windows users. There have a been a lot of bug fixes since 3.19.0. Also, we should align with Scala 2; users shouldn't have to wonder if differences in REPL behavior stem from the JLine versions being out of sync.
Unfortunately it's not as simple as bumping the version in project/Build.scala. Doing so breaks the repl task in our sbt build:
[error] java.lang.NoSuchMethodError: 'org.jline.utils.AttributedString org.jline.utils.AttributedString.fromAnsi(java.lang.String, java.util.List, java.lang.String, java.lang.String)'
[error] at org.jline.reader.impl.LineReaderImpl.fromAnsi(LineReaderImpl.java:4232)
[error] at org.jline.reader.impl.LineReaderImpl.expandPromptPattern(LineReaderImpl.java:4154)
[error] at org.jline.reader.impl.LineReaderImpl.setPrompt(LineReaderImpl.java:1253)
[error] at org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:628)
[error] at org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:512)
[error] at dotty.tools.repl.JLineTerminal.readLine(JLineTerminal.scala:75)
The cause is that sbt itself is still on 3.19.0, as per https://github.com/sbt/sbt/issues/7177 . On that ticket, @eed3si9n writes:
I don't think there's good solution for now
If console could fork, that would probably solve it, but that's not supported by sbt, as per https://github.com/sbt/sbt/issues/1918
Perhaps we could reimplement repl on top of runMain, rather than on top of console...? With runMain, we could fork.
A natural question is: Isn't Scala 2 affected? Could Scala 3 do the same thing?
In the Scala 2 build, the scala command in our sbt build (which runs the REPL when run with no arguments) is implemented on runMain. But we've got a different problem: the REPL runs, but many JLine features don't work, as per https://github.com/scala/scala-dev/issues/755
The workaround (as described on that ticket) is to launch the REPL from the shell rather than from sbt, but that's unsatisfying. Dale and I tried to fix it once; our abandoned attempt is at https://github.com/scala/scala/pull/9380
sbt itself is still on 3.19.0
Eugene has pointed out that sbt 1.10.0-M1 has taken the 3.24.1 upgrade. I will try to further bump it to 3.25.1: https://github.com/sbt/sbt/pull/7500
@Kordyjan @Gedochao I think it will be worth mentioning in the release notes for the versions where the JLine upgrade lands that sbt users will need to upgrade to 1.9.9 in order to continue using the console task to access the REPL; see https://github.com/scala/scala-dev/pull/861 for sample wording
