The latest development versions of 1.2.8 are available as nightly builds on sbt-maven-snapshots (https://repo.scala-sbt.org/scalasbt/maven-snapshots) repo.
Note that currently following the URL would lead you to Bintray, but /org/scala-sbt/sbt/ would actually point to a Jenkins server.
To use a nightly build:
sbt launcher will resolve the sbt core artifacts based on the specification.
Unless you’re debugging the
sbt script or the launcher JAR, you should be able to use any recent stable version of sbt installation as the launcher following the Setup instructions first.
If you’re overriding the repositories via
~/.sbt/repositories, make sure that there’s a following entry:
[repositories] ... sbt-maven-snapshots: https://repo.scala-sbt.org/scalasbt/maven-snapshots/, bootOnly