Scalac support for compiler plugins in jars with transitive dependencies

[pjfanning]

It appears that scalac and build tools that use scalac (sbt, Mill, etc.) require compiler plugins to have all the classes that the plugin needs inside one jar. Does anyone know if this understanding is incorrect?

This topic is based on these previously raised issues and forum topics:

• add some way to specify a dependency for a compiler plugin · Issue #7269 · sbt/sbt · GitHub
• Compiler plugins and dependencies - #5 by cbley
• Does not work with SBT Assembly · Issue #63 · gzoller/scala-reflection · GitHub

Any thoughts on this issue would be appreciated.

[SethTisue]

relevant: Option to specify classpath for compiler plugins · Issue #4841 · scala/bug · GitHub, SI-4841 Plugins get a class path by som-snytt · Pull Request #3169 · scala/scala · GitHub