Aot generated sources fail to compile with 'File name too long' error

[adisesha]

Steps to reproduce:

1. Go to start.spring
2. Project: Gradle-Kotlin
3. Language: Kotlin
4. Spring Boot: 3.0.1
5. Packaging: Jar
6. Java: 17
7. Dependencies: GraalVM Native Support, Spring Boot Actuator
8. Generate the project(attached generated project for convenience) and run ./gradlew nativeRun. I got the following error,

> Task :compileAotJava FAILED
/home/test/Downloads/actuator-bug/build/generated/aotSources/org/springframework/boot/actuate/autoconfigure/observation/ObservationAutoConfiguration__BeanDefinitions.java:115: error: error while writing OnlyMetricsMeterObservationHandlerConfiguration__BeanDefinitions: /home/test/Downloads/actuator-bug/build/classes/java/aot/org/springframework/boot/actuate/autoconfigure/observation/ObservationAutoConfiguration__BeanDefinitions$MeterObservationHandlerConfiguration__BeanDefinitions$OnlyMetricsMeterObservationHandlerConfiguration__BeanDefinitions.class: File name too long
    public static class OnlyMetricsMeterObservationHandlerConfiguration__BeanDefinitions {

Environment:

• Ubuntu 22.04.1 LTS
• openjdk 17.0.5 2022-10-18
• OpenJDK Runtime Environment GraalVM CE 22.3.0 (build 17.0.5+8-jvmci-22.3-b08)
• OpenJDK 64-Bit Server VM GraalVM CE 22.3.0 (build 17.0.5+8-jvmci-22.3-b08, mixed mode, sharing)

actuator-bug.zip

[mhalbritter]

Hm, I can't reproduce this. What's the filesystem of /home/test/Downloads?

[mhalbritter]

/home/test/Downloads/actuator-bug/build/classes/java/aot/org/springframework/boot/actuate/autoconfigure/observation/ObservationAutoConfiguration__BeanDefinitions$MeterObservationHandlerConfiguration__BeanDefinitions$OnlyMetricsMeterObservationHandlerConfiguration__BeanDefinitions.class is 286 chars long. The filename ObservationAutoConfiguration__BeanDefinitions$MeterObservationHandlerConfiguration__BeanDefinitions$OnlyMetricsMeterObservationHandlerConfiguration__BeanDefinitions.class is 170 chars long.

On my system (Fedora with BTRFS file system) the limits are:

$ getconf PATH_MAX ~
4096

$ getconf NAME_MAX ~
255

[adisesha]

The file system is ecryptfs

Results of getconf commands,

$ getconf PATH_MAX ~
4096

$ getconf NAME_MAX ~
143

[mhalbritter]

Well, that explains it. Not sure if we can do something here. I'll flag it as team attention to see what the team thinks.

[philwebb]

Suggestion from @wilkinsona would be to remove __BeanDefinitions for nested classes. E.g

ObservationAutoConfiguration__BeanDefinitions$MeterObservationHandlerConfiguration__BeanDefinitions$OnlyMetricsMeterObservationHandlerConfiguration__BeanDefinitions.class

Becomes

ObservationAutoConfiguration__BeanDefinitions$MeterObservationHandlerConfiguration$OnlyMetricsMeterObservationHandlerConfiguration.class

[snicoll]

Thanks for the suggestion. It turned out to be quite straightforward to change and a good thing regardless of this issue.

@adisesha the generated class names will be shorter, I hope it'll be enough for your env. Please give it a try and let us know if more optimizations are required. Thanks!

[adisesha]

@snicoll Thank you. It works.