Using Maven Plugin with Java 14 results in an exception

[ahofmeister]

• summary of problem
  Executing mvn spotless:apply using Java 14 results in an error executing the goal.
• gradle or maven version
  Apache Maven 3.8.1 (05c21c65bdfed0f71a2f2ada8b84da59348c4c5d)
• spotless version
  2.12.3
• operating system and version
  macOS Big Sur Version 11.5.2
• copy-paste your full Spotless configuration block(s), and a link to a public git repo that reproduces the problem if possible

https://github.com/ahofmeister/ReleaseManager

   <plugin>
                <groupId>com.diffplug.spotless</groupId>
                <artifactId>spotless-maven-plugin</artifactId>
                <version>2.12.3</version>
                <configuration>
                    <formats>
                        <format>
                            <includes>
                                <include>src/main/java/**/*.java</include>
                                <include>src/test/java/**/*.java</include>
                            </includes>
                            <!-- define the steps to apply to those files -->
                            <trimTrailingWhitespace/>
                            <endWithNewline/>
                            <indent>
                                <tabs>true</tabs>
                                <spacesPerTab>4</spacesPerTab>
                            </indent>
                        </format>
                    </formats>
                    <java>
                        <eclipse/>
                        <importOrder>
                            <order>java,javax,org,com,</order>
                        </importOrder>
                        <removeUnusedImports/>

                    </java>
                </configuration>
            </plugin>

• copy-paste the full content of any console errors emitted by gradlew spotless[Apply/Check] --stacktrace

[ERROR] Failed to execute goal com.diffplug.spotless:spotless-maven-plugin:2.12.3:apply (default-cli) on project demo: 
Execution default-cli of goal com.diffplug.spotless:spotless-maven-plugin:2.12.3:apply failed: 
java.lang.reflect.InvocationTargetException: class com.google.googlejavaformat.java.RemoveUnusedImports (in unnamed 
module @0x7440265c) cannot access class com.sun.tools.javac.util.Context (in module jdk.compiler) because module 
jdk.compiler does not export com.sun.tools.javac.util to unnamed module @0x7440265c -> [Help 1]

java.lang.reflect.InvocationTargetException
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:568)
        at com.diffplug.spotless.java.GoogleJavaFormatStep$State.lambda$constructRemoveUnusedFunction$3(GoogleJavaFormatStep.java:190)
        at com.diffplug.spotless.java.GoogleJavaFormatStep$State.lambda$createRemoveUnusedImportsOnly$1(GoogleJavaFormatStep.java:167)
        at com.diffplug.spotless.FormatterFunc.apply(FormatterFunc.java:32)
        at com.diffplug.spotless.FormatterStepImpl$Standard.format(FormatterStepImpl.java:78)
        at com.diffplug.spotless.FormatterStep$Strict.format(FormatterStep.java:76)
        at com.diffplug.spotless.Formatter.compute(Formatter.java:230)
        at com.diffplug.spotless.PaddedCell.calculateDirtyState(PaddedCell.java:201)
        at com.diffplug.spotless.PaddedCell.calculateDirtyState(PaddedCell.java:188)
        at com.diffplug.spotless.maven.SpotlessApplyMojo.process(SpotlessApplyMojo.java:45)
        at com.diffplug.spotless.maven.AbstractSpotlessMojo.execute(AbstractSpotlessMojo.java:150)
        at com.diffplug.spotless.maven.AbstractSpotlessMojo.execute(AbstractSpotlessMojo.java:141)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:210)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:156)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81)
        at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:56)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:305)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:192)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:105)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:957)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:289)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:193)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:568)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:282)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:225)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:406)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:347)
Caused by: java.lang.IllegalAccessError: class com.google.googlejavaformat.java.RemoveUnusedImports (in unnamed module @0x7440265c) cannot access class com.sun.tools.javac.util.Context (in module jdk.compiler) because module jdk.compiler does not export com.sun.tools.javac.util to unnamed module @0x7440265c
        at com.google.googlejavaformat.java.RemoveUnusedImports.removeUnusedImports(RemoveUnusedImports.java:188)
        ... 37 more

[nedtwigg]

I believe this is a dupe of / new info for #834. Try this workaround and lemme know if that fixes it. If so, we'll close this as dupe and update #834 to note that it affects Java 14 as well.

[ahofmeister]

@nedtwigg Thanks, it works with

export MAVEN_OPTS='--add-exports=java.base/jdk.internal.module=ALL-UNNAMED --add-exports jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED   --add-exports jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED   --add-exports jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED   --add-exports jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED --add-exports jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED   --add-exports jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED'

I had to add the javac.api as well.