Incremental compilation always recompiles all

I always get this:

Pruning sources from previous analysis, due to incompatible CompileSetup.

and a full recompile.

My pom.xml is:

<plugin>
	<groupId>org.apache.maven.plugins</groupId>
	<artifactId>maven-compiler-plugin</artifactId>
	<version>3.8.0</version>
	<configuration>
		<source>${build.jdk.version}</source>
		<target>${build.jdk.version}</target>
		<encoding>UTF-8</encoding>
		<compilerArgs>
			<arg>--add-modules</arg><arg>ALL-SYSTEM</arg>
		</compilerArgs>
	</configuration>
</plugin>

<plugin>
	<groupId>net.alchim31.maven</groupId>
	<artifactId>scala-maven-plugin</artifactId>
	<version>${version.scala-maven-plugin}</version>
	<configuration>
		<compilerPlugins>
			<compilerPlugin>
				<groupId>com.artima.supersafe</groupId>
				<artifactId>supersafe_${version.scalalibs}</artifactId>
				<version>${version.supersafe}</version>
			</compilerPlugin>
		</compilerPlugins>
		<jvmArgs>
			<jvmArg>-Xms64m</jvmArg>
			<jvmArg>-Xss4m</jvmArg>
			<jvmArg>-Xmx2g</jvmArg>
		</jvmArgs>
		<args>
			<arg>-release</arg>
			<arg>${build.jdk.version}</arg>
		</args>
		<scalaVersion>${version.scalalibs}</scalaVersion>
		<recompileMode>incremental</recompileMode>
	</configuration>
</plugin>

version.scalalibs=2.12.7 build.jdk.version=10 version.supersafe=1.1.7 version.scala-maven-plugin=3.4.4

Any hints?

[SethTisue]

I’m surprise by the usage of this plugin in an ecosystem where sbt is the defacto build tool.

if you participate in Scala OSS and watch conference talks, it’s easy to get the impression that sbt use is near-universal.

but if you talk to people who are just quietly using Scala at work, you get a different impression: Maven and Gradle use seems rather common, especially at big companies. (in a Java shop, it can be easier to get a new language in the door than it is to convince co-workers to switch build tools.)

[davidB]

@jvican

Would you guys be free to jump on a call to talk about the future of Scala support in Maven?

Yes, it depends of the time window (I’m in France, and Friday is often a better day for a call with me, less constraint). FYI Scala, is no longer my daily job or my favorite language.