Dokka regularly OOMs gradle in a simple project

[ZacSweers]

Describe the bug
I have a small project that, when I run all the dokkaHtml tasks on my relatively powerful personal machine, easily exhausts Gradle's default memory configuration for a build

Expected behaviour
I understand nothing is free, but I think Dokka shouldn't OOM a trivial project and my first thought was there might be a memory leak.

Screenshots
N/A

To Reproduce
Check out this project and run ./gradlew dokkaHtml locally

Dokka configuration
Standard configuration

Installation

• Operating system: macOS
• Build tool: Gradle 6.6
• Dokka version: 1.4.10

Additional context
Add any other context about the problem here

[ZacSweers]

Example failure https://github.com/ZacSweers/MoshiX/runs/1173513315

[Kordyjan]

This duplicates #1405. It is worth noting that it is not a simple memory leak because jvm is running out of metaspace and not heap space. We are still investigating that. We had a few ideas where it is coming from but all of them turned out to be false.

For now you can increase your metaspace as a workaround. Just put org.gradle.jvmargs=-XX:MaxMetaspaceSize=512m in gradle.properties. For some bigger projects 1G may be necessary instead of 512m.