Unused SLF4j Logger created with lomboks @Slf4j annotation creates exception

[timmhirsens]

Description of the problem

Unused SLF4j Logger created with lomboks @Slf4j annotation creates exception during error_prone static analysis:

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Given the following class

import lombok.extern.slf4j.Slf4j;
@Slf4j
public class TestClass {
	public void test() {
		System.out.println("Hello");
	}
}

Running mvn compile with the following configuration in pom.xml

			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<configuration>
					<target>${java.version}</target>
					<source>${java.version}</source>
					<compilerArgs>
						<arg>-XDcompilePolicy=simple</arg>
						<arg>-Xplugin:ErrorProne</arg>
					</compilerArgs>
					<annotationProcessorPaths>
						<path>
							<groupId>org.mapstruct</groupId>
							<artifactId>mapstruct-processor</artifactId>
							<version>${org.mapstruct.version}</version>
						</path>
						<path>
							<groupId>org.projectlombok</groupId>
							<artifactId>lombok</artifactId>
							<version>1.18.18</version>
						</path>
						<dependency>
							<groupId>org.projectlombok</groupId>
							<artifactId>lombok-mapstruct-binding</artifactId>
							<version>0.2.0</version>
						</dependency>
						<path>
							<groupId>org.springframework</groupId>
							<artifactId>spring-context-indexer</artifactId>
							<version>5.3.4</version>
						</path>
						<path>
							<groupId>org.springframework.boot</groupId>
							<artifactId>spring-boot-configuration-processor</artifactId>
							<version>${spring.boot.version}</version>
						</path>
						<path>
							<groupId>com.google.errorprone</groupId>
							<artifactId>error_prone_core</artifactId>
							<version>2.5.1</version>
						</path>
					</annotationProcessorPaths>
					<forceJavacCompilerUse>true</forceJavacCompilerUse>
				</configuration>

Creates the following error:

[ERROR] TestClass.java:[1] error: An unhandled exception was thrown by the Error Prone static analysis plugin.
[ERROR]      Please report this at https://github.com/google/error-prone/issues/new and include the following:
[ERROR]   
[ERROR]      error-prone version: 2.5.1
[ERROR]      BugPattern: UnusedVariable
[ERROR]      Stack Trace:
[ERROR]      java.lang.IndexOutOfBoundsException
[ERROR] -> [Help 1]

What version of Error Prone are you using?

2.5.1

Have you found anything relevant by searching the web?

There seems to be earlier issues with lombok & error-prone

[cushon]

#1250