Disable checkerframework Gradle plugin by default.

See comment.

Author: olafurpg

lsif-java/src/main/scala/com/sourcegraph/lsif_java/buildtools/GradleBuildTool.scala

@@ -78,7 +78,17 @@ class GradleBuildTool(index: IndexCommand) extends BuildTool("Gradle", index) {
       buildCommand +=
         s"-Porg.gradle.java.installations.paths=${toolchains.paths()}"
     }
-    buildCommand ++= index.finalBuildCommand(List("clean", "compileTestJava"))
+    buildCommand ++=
+      index.finalBuildCommand(
+        List(
+          // Disable the checkerframework plugin because it updates the processorpath
+          // in a way that causes the error "plug-in not found: semanticdb".
+          // Details: https://github.com/kelloggm/checkerframework-gradle-plugin/blob/76d1926ae22144b082dfcfde1abe625750469398/src/main/groovy/org/checkerframework/gradle/plugin/CheckerFrameworkPlugin.groovy#L374-L376
+          "-PskipCheckerFramework",
+          "clean",
+          "compileTestJava"
+        )
+      )
     buildCommand += lsifJavaDependencies
 
     val result = index.process(buildCommand, env = Map("TERM" -> "dumb"))

tests/buildTools/src/test/scala/tests/BaseBuildToolSuite.scala

@@ -76,7 +76,7 @@ abstract class BaseBuildToolSuite extends MopedSuite(LsifJava.app) {
       if (semanticdbFiles.length != expectedSemanticdbFiles) {
         fail(
           s"Expected $expectedSemanticdbFiles SemanticDB file(s) to be generated.",
-          clues(semanticdbFiles)
+          clues(semanticdbFiles, app.capturedOutput)
         )
       }
       if (expectedPackages.nonEmpty) {

tests/buildTools/src/test/scala/tests/GradleBuildToolSuite.scala

@@ -207,4 +207,30 @@ class GradleBuildToolSuite extends BaseBuildToolSuite {
     2, // Two files because `conf/routes` generates a Java file.
     initCommand = gradleVersion("6.8")
   )
+
+  checkBuild(
+    "checkerframework",
+    """|/build.gradle
+       |plugins {
+       |    id 'java'
+       |    id 'org.checkerframework' version '0.5.24'
+       |}
+       |repositories {
+       |    mavenCentral()
+       |}
+       |java {
+       |  toolchain {
+       |    languageVersion = JavaLanguageVersion.of(8)
+       |  }
+       |}
+       |/src/main/java/foo/Example.java
+       |package foo;
+       |public class Example {}
+       |/src/test/java/foo/ExampleSuite.java
+       |package foo;
+       |public class ExampleSuite {}
+       |""".stripMargin,
+    2,
+    initCommand = gradleVersion("6.8.3")
+  )
 }