When publishing our plugin we got this
[info] Done packaging.
[trace] Stack trace suppressed: run last *:publish for the full output.
[error] (*:publish) java.io.IOException: PUT operation to URL https://nexus.mycompany.com/repository/maven-snapshots/com/foo/foo-sbt-plugin_2.10_0.13/1.0.0-SNAPSHOT/foo-sbt-plugin-1.0.0-SNAPSHOT.pom failed with status code 400: Invalid path for a Maven 2 repository
We set up the plugin using
sbtPlugin := true
publishMavenStyle := true