gradle can't find lombok generated constructor in integration test

I believe the crucial bit that you are missing is an annotation processor configuration for your integrationTest source set:

    integrationTestAnnotationProcessor "org.projectlombok:lombok:1.18.6"

---

In the following, you can find a self-contained, working example (tested with Gradle 5.3.1). It’s not exactly your project but should be close enough to get you on track:

build.gradle

apply plugin: 'java'

sourceSets {
    integrationTest {
        java.srcDir 'src/testInteg/java'
        resources.srcDir 'src/testInteg/resources'
    }
}

configurations {
    integrationTestImplementation.extendsFrom testImplementation
    integrationTestRuntimeOnly.extendsFrom testRuntimeOnly
}

task integrationTest(type: Test) {
    testClassesDirs = sourceSets.integrationTest.output.classesDirs
    classpath = sourceSets.integrationTest.runtimeClasspath + sourceSets.test.runtimeClasspath
}

repositories {
    jcenter();
}

dependencies {
    implementation "org.projectlombok:lombok:1.18.6"

    testImplementation "junit:junit:4.11"

    integrationTestAnnotationProcessor "org.projectlombok:lombok:1.18.6"
}

src/testInteg/java/MyTest.java

public class MyTest {

  @org.junit.Test
  public void test() {
    new Person("foo", "bar");
    assert true;
  }

  @lombok.AllArgsConstructor
  private class Person {
    private String id;
    private String name;
  }
}

I also found the same issue and fixed by adding testAnnotationProcessor beside annotationProcessor to build.gradle:

annotationProcessor "org.projectlombok:lombok:${lombok_version}"
testAnnotationProcessor "org.projectlombok:lombok:${lombok_version}"