**Problem**
Compiler bridge resolution calls out to Coursier,
and it shows up on the profiler.
**Solution**
This uses sbt 2.x caching to cache the prebuilt compiler bridge binaries
to avoid calling Coursier from second time onwards.
**Problem**
During the milestone releases of Scala, e.g. Scala 2.13.0-M1,
scalaBinaryVersion by design points to 2.13.0-M1,
and also the source directory uses scala-2.13.0-M1,
but in most cases we actually want to pretend compatibility
and use scala-2.13 directory.
**Solution**
This introduces a new setting called scalaEarlyVersion,
which is the scalaBinaryVersion of the release version of milestones.
We have been calling this "partial version", but that broke
down for Scala 3, which adopted semantic versioning.
**Problem**
On IntelliJ the users are getting the hint to upgrade to -Xsource:3
style, however the supported syntax do not parse.
**Solution**
This adds -Xsource:3 to the parser. The metabuild compilation uses
-Xsource:3 since sbt 1.6.0.
**Problem**
Protobuf reading shows up as one of the bottlenecks during no-op compilation.
**Solution**
This adds a local, in-memory cache of Zinc Analysis using the timestamp
and the file size of the persisted protobuf file.
**Problem**
sha256 is currently a bottleneck for no-op compilation.
**Solution**
This adds a local, in-memory cache of sha256 hashes of binary files
using their timestamp and file size.
The size of the digest cache can be configured using localDigestCacheByteSize,
which is set to 1MB by default.
**Problem**
Scala 3.8 REPL won't work since they've split the repl artifact into another JAR.
**Solution**
This works around it by creating a yet-another sandbox configuration ScalaReplTool
(similar to ScalaTool and ScalaDocTool) and a separate scalaInstance for
console task, so when Zinc is invoked we'll be able to conjure the right array of JARs.
**Problem**
For sbt 1.x, the user is forced to pick between having a stable ID for the root project,
or having the automatic aggregation of all subprojects.
The problem becomes more pronounced for large build that frequent add/remove subprojects.
**Solution**
This implements `.autoAggregate` method on `Project`, which is implemented as
`this.aggregate(LocalAggregate)`.
At the loading time, we can automatically expand `LocalAggregate` to a list of subproject references,
after we discover all subprojects.
The `autoAggregate` will use the base directory of the subproject to pick the parent-child
relationship. For example, a root project would aggregate all subprojects,
but `bar` might aggregate only `bar/bar1` and `bar/bar2`.
**Problem**
Client-side run currently fails on JDK 8 because sbtn
creates args file even though JDK 8 does not support it.
This is likely because sbtn is compiled using GraalVM on a modern JDK.
**Solution**
This adds a new fork option canUseArgumentsFile to delegate the args file decision
to the server, and default to false if the value is missing.
This retroactively fixes sbt 2.x client-side run.
**Problem**
managedScalaInstance := false fails Java-only tests because
the test runner is based on a Scala Runner and sbt 2.x
currently derives the ScalaInstance only from update.
**Solution**
For the purpose of Java-only testing, create a dummy Scala Instance.
**Problem**
Scala 3.8.0 nightly and later in-sources the scala-library for the use by Scala 3, as opposed to using Scala-2.13-bound standard library.
This means that we will run into situations where scala-library should NOT align with scala-reflect, which might exist transitively.
**Solution**
Adjust the csrSameVersions rule for Scala 3.8 so it will only try to keep scala-library and scala3-library versions aligned.
Eugene Yokota
Hamza Remmal
Aleksandra Zdrojowa
xuwei-k
Billy Autrey