Additional-spring-configuration-metadata.json only merges with the configurationProperties generated metadata on second build - maven

Question

I have a kotlin spring boot auto configuration project. It has a class Annotated with #ConfigurationProperties. This generates the property metadata file as expected. I want to add a property that does not come from the #ConfigurationProperties class. As documented, to do that I should create my own additional-spring-configuration-metadata.json file.
I found that the first time I run mvn clean package, the metadata is generated without including the info from additional-spring-configuration-metadata.json. The second time I run mvn package (assuming I didn't do a clean) the metadata includes the info from additional-spring-configuration-metadata.json
Why is this? How do I fix it to generate the data first time everytime?
My pom is below:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.7.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.redacted.entity.autoconfigure</groupId>
<artifactId>mongo-autoconfiguration</artifactId>
<version>1.0.0</version>
<name>mongo-autoconfiguration</name>
<description>AutoConfiguration for mongo</description>
<properties>
<java.version>1.8</java.version>
<kotlin.version>1.3.50</kotlin.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-autoconfigure</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-autoconfigure-processor</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-reflect</artifactId>
</dependency>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-stdlib-jdk8</artifactId>
</dependency>
</dependencies>
<build>
<sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
<testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>
<plugins>
<plugin>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-maven-plugin</artifactId>
<executions>
<execution>
<id>kapt</id>
<goals>
<goal>kapt</goal>
</goals>
<configuration>
<sourceDirs>
<sourceDir>src/main/kotlin</sourceDir>
</sourceDirs>
<annotationProcessorPaths>
<annotationProcessorPath>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-autoconfigure-processor</artifactId>
<version>2.1.7.RELEASE</version>
</annotationProcessorPath>
<annotationProcessorPath>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<version>2.1.7.RELEASE</version>
</annotationProcessorPath>
</annotationProcessorPaths>
</configuration>
</execution>
<execution>
<id>compile</id>
<goals>
<goal>compile</goal>
</goals>
</execution>
</executions>
<configuration>
<args>
<arg>-Xjsr305=strict</arg>
</args>
<compilerPlugins>
<plugin>spring</plugin>
</compilerPlugins>
</configuration>
<dependencies>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-maven-allopen</artifactId>
<version>${kotlin.version}</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
</project>
UPDATE: I added a solution below but I still have a bounty open. I will award it if someone finds a less cumbersome way of solving the problem

Answer 1

I fixed it by adding in the mvn copy resources plugin to copy the additional-spring-configuration-metadata.json file in the process-sources phase so it can be available when kapt runs.
additional-spring-configuration-metadata.json
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.1.0</version>
<executions>
<execution>
<id>copy-resources</id>
<!-- here the phase you need -->
<phase>process-sources</phase>
<goals>
<goal>copy-resources</goal>
</goals>
<configuration>
<outputDirectory>${basedir}/target/classes/META-INF</outputDirectory>
<resources>
<resource>
<directory>src/main/resources/META-INF</directory>
<includes>
<include>
additional-spring-configuration-metadata.json
</include>
</includes>
</resource>
</resources>
</configuration>
</execution>
</executions>
</plugin>

Answer 2

You may be running into a bug that the kapt goal is not running - https://youtrack.jetbrains.com/issue/KT-18022. Even though that is marked as fixed there are recent comments of other reports with same issue.