Unresolved dependencies path

I have been using Scala 3 RC2 with sbt for a while on one computer, and I decided to start using it on another. I copied build.sbt and tried to compile, but I am getting “Unresolved dependencies path” (see below for details). Does anyone know what the problem might be? I confirmed that I have the same version of sbt on both machines (1.4.6). Thanks.

[info] welcome to sbt 1.4.6 (Oracle Corporation Java 1.8.0_91)
[info] loading project definition from /home/rpaielli/trajspec/project
[info] loading settings for project trajspec from build.sbt …
[info] set current project to trajspec (in build file:/home/rpaielli/trajspec/)
[warn]
[warn] Note: Unresolved dependencies path:
[error] sbt.librarymanagement.ResolveException: Error downloading org.scala-lang:scala-library:3.0.0-RC2
[error] Not found
[error] Not found
[error] not found: /home/rpaielli/.ivy2/localorg.scala-lang/scala-library/3.0.0-RC2/ivys/ivy.xml
[error] not found: https://repo1.maven.org/maven2/org/scala-lang/scala-library/3.0.0-RC2/scala-library-3.0.0-RC2.pom
[error] at lmcoursier.CoursierDependencyResolution.unresolvedWarningOrThrow(CoursierDependencyResolution.scala:258)
[error] at lmcoursier.CoursierDependencyResolution.$anonfun$update$38(CoursierDependencyResolution.scala:227)
[error] at scala.util.Either$LeftProjection.map(Either.scala:573)
[error] at lmcoursier.CoursierDependencyResolution.update(CoursierDependencyResolution.scala:227)
[error] at sbt.librarymanagement.DependencyResolution.update(DependencyResolution.scala:60)
[error] at sbt.internal.LibraryManagement$.resolve$1(LibraryManagement.scala:53)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$12(LibraryManagement.scala:103)
[error] at sbt.util.Tracked$.$anonfun$lastOutput$1(Tracked.scala:73)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$20(LibraryManagement.scala:116)
[error] at scala.util.control.Exception$Catch.apply(Exception.scala:228)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$11(LibraryManagement.scala:116)
[error] at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$11$adapted(LibraryManagement.scala:97)
[error] at sbt.util.Tracked$.$anonfun$inputChangedW$1(Tracked.scala:219)
[error] at sbt.internal.LibraryManagement$.cachedUpdate(LibraryManagement.scala:130)
[error] at sbt.Classpaths$.$anonfun$updateTask0$5(Defaults.scala:3486)
[error] at scala.Function1.$anonfun$compose$1(Function1.scala:49)
[error] at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62)
[error] at sbt.std.Transform$$anon$4.work(Transform.scala:68)
[error] at sbt.Execute.$anonfun$submit$2(Execute.scala:282)
[error] at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:23)
[error] at sbt.Execute.work(Execute.scala:291)
[error] at sbt.Execute.$anonfun$submit$1(Execute.scala:282)
[error] at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:265)
[error] at sbt.CompletionService$$anon$2.call(CompletionService.scala:64)
[error] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
[error] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
[error] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
[error] at java.lang.Thread.run(Thread.java:745)
[error] (update) sbt.librarymanagement.ResolveException: Error downloading org.scala-lang:scala-library:3.0.0-RC2
[error] Not found
[error] Not found
[error] not found: /home/rpaielli/.ivy2/localorg.scala-lang/scala-library/3.0.0-RC2/ivys/ivy.xml
[error] not found: https://repo1.maven.org/maven2/org/scala-lang/scala-library/3.0.0-RC2/scala-library-3.0.0-RC2.pom
[error] Total time: 2 s, completed Apr 15, 2021 10:59:35 AM

You may be missing addSbtPlugin("ch.epfl.lamp" % "sbt-dotty" % "0.5.4") in project/plugins.sbt.

This is no longer needed if you upgrade to sbt 1.5.0.

Yes, that was it. I had forgotten about that. Thanks!