Spring + GraalVM throws new method found exception even after running the tracing agent

> UPDATE: See the answer for the correct (and much simpler) steps to train and build the native image.

I've been trying to create Spring Boot native build steps without manually adding any configuration, relying entirely on the GraalVM Tracing Agent to discover everything.

It works fine, until I "hide" a manual Jackson ObjectMapper call in the service layer, that relies on reflection.

Then the GraalVM native-image build's image creation step breaks and complains about the "hidden" method, that should have been discovered by the tracing agent (see steps 3-5 below).

[7/7] Creating image... (0.0s @ 3.14GB)

Fatal error: com.oracle.svm.core.util.VMError$HostedError: com.oracle.svm.core.util.VMError$HostedError: New Method or Constructor found as reachable after static analysis: public java.lang.String com.tlvlp.springnativedemo.AppendRequest.appendWith()

I think the problem might be that either the hints for the reflection call are somehow not collected or they don't end up in the right place for the native-image tool to pick it up, but I have run out of ideas to try so I appreciate any guidance.

Versions:

• Java 17
• GraalVM 22.3.r17
• Spring Boot 3.1.0 (should already contain fixes for a similar issue reported earlier).

Steps to reproduce

This is the demo project that I was experimenting on. Details are in the README and there the steps + training are triggered by scripts in the project's root.

1. Run a Spring Boot native build to create the initial hints & classes, otherwise the tracing agent will not start. (Would be really nice to eliminate this overhead)

mvn clean package -DskipTests -Pnative

2. Package the generated hints + classes under META-INF into the jar.

mvn package -DskipTests

3. Start the tracing agent to append the existing hints.

"$GRAALVM_HOME"/bin/java \
    -Dspring.aot.enabled=true \
    -agentlib:native-image-agent=config-merge-dir="$(pwd)"/target/classes/META-INF/native-image \
    -jar "$INPUT_JAR_PATH"

4. Call the service endpoint to make every internal method call visible for the tracing agent.
5. Stop the tracing agent.
6. Package the generated hints + classes under META-INF into the jar.
7. Unpack the jar to a separate folder (as advised in the Spring Boot native guide)

rm -rf "$NATIVE_BUILD_DIR"
mkdir -p "$NATIVE_BUILD_DIR"
cd "$NATIVE_BUILD_DIR" || exit 1
jar -xvf $INPUT_JAR_WITH_NATIVE_HINTS

8. Run the native-image build tool

"$GRAALVM_HOME"/bin/native-image \
--no-fallback \
-H:Name=$OUTPUT_EXECUTABLE_NAME \
-cp .:BOOT-INF/classes:`find BOOT-INF/lib | tr '\n' ':'` || exit 1

That error is related using "record" for AppendRequest, if you check github issues you will see there were sometimes it was not working very friendly with graalvm, after I convert that to class like below everything worked as expected.

package com.tlvlp.springnativedemo;

import jakarta.validation.constraints.NotEmpty;
import lombok.Data;

@Data
public class AppendRequest {
        @NotEmpty
        String appendWith;
}

for tracing I used command below

java -agentlib:native-image-agent=config-output-dir=./src/main/resources/META-INF/native-image/ -jar target/native-test.jar

for generating the native image used

mvn -Pnative native:compile

for calling the service

curl -X 'POST'   'http://localhost:8080/append'   -H 'accept: application/json'   -H 'Content-Type: application/json'   -d '{}'

response

{"appended":"START-null"}

and server side logs