Modules that export same package to same third module causes runtime error

[telpirion]

Issue Description

Adding the Google Cloud Vertex AI library for Java to a MDK build.gradle file causes a runtime error:

Exception in thread "main" java.lang.reflect.InvocationTargetException
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Unknown Source)
        at java.base/java.lang.reflect.Method.invoke(Unknown Source)
        at net.minecraftforge.bootstrap.Bootstrap.bootstrapMain(Bootstrap.java:133)
        at net.minecraftforge.bootstrap.Bootstrap.start(Bootstrap.java:53)
        at net.minecraftforge.bootstrap.ForgeBootstrap.main(ForgeBootstrap.java:19)
Caused by: java.lang.module.ResolutionException: Modules gax.grpc and proto.google.common.protos export package com.google.longrunning to module io.grpc.util
        at java.base/java.lang.module.Resolver.resolveFail(Unknown Source)
        at java.base/java.lang.module.Resolver.failTwoSuppliers(Unknown Source)
        at java.base/java.lang.module.Resolver.checkExportSuppliers(Unknown Source)
        at java.base/java.lang.module.Resolver.finish(Unknown Source)
        at java.base/java.lang.module.Configuration.<init>(Unknown Source)
        at java.base/java.lang.module.Configuration.resolveAndBind(Unknown Source)
        at java.base/java.lang.module.Configuration.resolveAndBind(Unknown Source)
        at net.minecraftforge.bootstrap@2.1.7/net.minecraftforge.bootstrap.Bootstrap.moduleMain(Bootstrap.java:166)
        ... 5 more

Repro steps

1. Download the current MDK and go through set up steps.
2. Add the following code to build.gradle.

    minecraftLibrary platform('com.google.cloud:libraries-bom:26.59.0')
    minecraftLibrary("com.google.cloud:google-cloud-vertexai:1.20.1")
    minecraftLibrary("com.google.api.grpc:proto-google-cloud-vertexai-v1:1.1.0")

1. Run the runClient Gradle task.

Expected result: Minecraft launches
Actual result: runtime error (see issue description).

Environment

• MacOS
• VSCode
• Vertex AI library v1.20.1
• MDK downloaded from Forge site

Troubleshooting steps:

I have looked on the ForgeGradle public forum and found similar issues:

• https://forums.minecraftforge.net/topic/123078-problem-with-adding-wthit-as-dependency-solved/#comment-535211
• https://forums.minecraftforge.net/topic/119601-cant-include-dependency/#comment-524370

Steps tried to fix this issue:

• Changed the order of the Gradle plugins in my build.gradle
• Added an exclude block to my minecraftLibrary dependencies
• Changed Gradle version
• Reviewed documentation, including this page

Suggestions

I don't know what the root cause of this issue is, although I suspect that it might be related to the issue discussed in #624 . I would update the public documentation for ForgeGradle to include troubleshooting tips or work arounds for this issue. If this is a known issue, then it should be stated.

[Jonathing]

Still missing a couple of things to better understand this.

• ForgeGradle version?
• Gradle version? (it's in gradle/wrapper/gradle-wrapper.properties)
• Do other libraries work with minecraftLibrary with your setup?

[telpirion]

Code can be found here.

[Jonathing]

Ah ok, that answers that. Thanks.

[telpirion]

ForgeGradle version: net.minecraftforge.gradle' version '[6.0.24,6.2)'
Gradle version: distributionUrl=https\://services.gradle.org/distributions/gradle-8.12.1-bin.zip

I haven't tried other libraries, but I will give one a try now. Thanks for the quick response!

[Jonathing]

Yup. I'm not on Mac, but I'll try and replicate this setup to see what's going on. If I had to take a gut feeling guess, I think FG6 is not playing nice with the chained platform call.

[telpirion]

Yup. I'm not on Mac, but I'll try and replicate this setup to see what's going on. If I had to take a gut feeling guess, I think FG6 is not playing nice with the chained platform call.

I bet you are correct. FWIW, this dependency works fine:

    minecraftLibrary("com.google.code.gson:gson:2.12.1")

[Jonathing]

That tracks. Though, Minecraft already uses GSON itself. Just in case, try a library it doesn't use (like JGit or something 🤷)

[LexManos]

Just as a note, setting this flag may provide more information in the logs.

But also, verify that the libraries you're adding arnt shading in the same packages. That's not something that is allowed in java module system. And would require you to do some hacks workaround jnngradlemif that's the case.

[Jonathing]

Yes, it looks like this is precisely the case. Here's a search result for all instances of package com.google.longrunning; with the *.java file mask.

So, your error is exactly what it says it is. While it's not entirely obvious that Forge does this (unless you've read our forum posts lately), Forge bootstraps a module environment for Minecraft to run in, including all mods which each are their own module. In vanilla Minecraft and minimal loaders such as Fabric Loader, this doesn't happen because they do not use JPMS. So Lex is right, you're going to need to do some hacks to workaround this.

The reason your game did not crash when you had these as implementation as shown in your code you linked is because they are included as normal mods as if they were placed directly into the mods folder (more accurately they are loaded into the game layer). It's likely that Forge saw that they weren't valid mods and just skipped over them.

[telpirion]

That tracks. Though, Minecraft already uses GSON itself. Just in case, try a library it doesn't use (like JGit or something 🤷)

JGit also works just fine.

Just as a note, setting this flag may provide more information in the logs.

But also, verify that the libraries you're adding arnt shading in the same packages. That's not something that is allowed in java module system. And would require you to do some hacks workaround jnngradlemif that's the case.

I've attached the complete dump from my logs.

logs.txt

[telpirion]

I think my take away is that "I can't get there from here," which is too bad. I really do like the Forge MDK and its ecosystem -- keep up the good work!

I'll leave this issue open for you to close (or not) as you see fit.

[LexManos]

You would have to merge the libraries into one jar. Which isn't a difficult task.
But my suspicion was correct. The library you want to use isn't compatible with the JPMS. Which is something outside our control. And something Java is forcing on everyone in the future. So best bet is to report the issue to the authors. And do some workarounds until then.

[Jonathing]

Closing as out-of-scope.

I really do like the Forge MDK and its ecosystem -- keep up the good work!

Thank you!