This plugin is no longer actively developed, but we do continue to release a new version whenever a new Scala 2.12.x version comes out.
In Scala 2.13, the plugin's functionality has been included in the compiler directly under the -Ymacro-annotations flag. (Regardless, its status remains the same: experimental, API subject to change.)
http://docs.scala-lang.org/overviews/macros/paradise.html
Do it on your own machine. The GPG key is used for scala modules, talk to @lrytz if you need the passphrase.
Update the scalaVersion in the build, and the version if needed,
point your JAVA_HOME to Java 8, then
$> java -version
openjdk version "1.8.0_222"
OpenJDK Runtime Environment (AdoptOpenJDK)(build 1.8.0_222-b10)
OpenJDK 64-Bit Server VM (AdoptOpenJDK)(build 25.222-b10, mixed mode)
$> export SONATYPE_USERNAME=⛄️ SONATYPE_PASSWORD=🌨
$> sbt clean publishSigned sonaRelease
$> git tag -s -m "2.1.1 for Scala 2.12.XY" v2.1.1_2.12.XY HEAD
$> git push upstream v2.1.1_2.12.XY