I'm using Forgelin and created an object, annotated it with Mod, which didn't work. I then tried to import net.minecraftforge.fml.common.Mod, but that throws an 'unresolved reference' error. I'm in IDEA and, if it helps, Forge and Minecraft are not in my External Libraries. Sorry if Forgelin isn't directly supported, I didn't know where else to ask. Oh yeah, and genIntellijRuns throws a NullPointerException! 

Edited February 23, 20196 yr by fieldbox

Are you on 1.12 or 1.13?

On 1.12 the first task to run is setupDecompWorkspace (after importing the build.gradle).

On 1.13 I think the standard setup is just importing the build.gradle?  Correct me if I'm wrong; still working 1.12 myself.

 

I have 0 exp. with Forgelin / Kotlin so I can't directly help with any java/kotlin differences.

Edited February 23, 20196 yr by Laike_Endaril

I am on 1.12, I ran setupDecompWorkspace and I got genIntellijRuns working, but this still doesn't seem to work. Kotlin differences don't matter; I believe copying Java code into a Kotlin file will convert it anyway.

I changed things around in the "repositories" part of the gradle file (looks like my other repositories part was blocking out the official one with the forge stuff). Now there's a new issue:

 Could not find net.minecraftforge.gradle:ForgeGradle:2.3-SNAPSHOT.
     Searched in the following locations:
         https://jcenter.bintray.com/net/minecraftforge/gradle/ForgeGradle/2.3-SNAPSHOT/maven-metadata.xml
         https://jcenter.bintray.com/net/minecraftforge/gradle/ForgeGradle/2.3-SNAPSHOT/ForgeGradle-2.3-SNAPSHOT.pom
         https://jcenter.bintray.com/net/minecraftforge/gradle/ForgeGradle/2.3-SNAPSHOT/ForgeGradle-2.3-SNAPSHOT.jar
         http://maven.shadowfacts.net/net/minecraftforge/gradle/ForgeGradle/2.3-SNAPSHOT/maven-metadata.xml
         http://maven.shadowfacts.net/net/minecraftforge/gradle/ForgeGradle/2.3-SNAPSHOT/ForgeGradle-2.3-SNAPSHOT.pom
         http://maven.shadowfacts.net/net/minecraftforge/gradle/ForgeGradle/2.3-SNAPSHOT/ForgeGradle-2.3-SNAPSHOT.jar
     Required by:
         :mod:unspecified

That error appears in the Gradle window for IDEA as well as setupDecompWorkspace.

I haven't tried editing that part of the build file, so I'm not the best one to answer, but...
 

buildscript {
    repositories {
        jcenter()
        maven { url = "http://files.minecraftforge.net/maven" }
    }
    dependencies {
        classpath 'net.minecraftforge.gradle:ForgeGradle:2.3-SNAPSHOT'
    }
}
apply plugin: 'net.minecraftforge.gradle.forge'
//Only edit below this line, the above code adds and enables the necessary things for Forge to be setup.

^ There's a comment there which says not to edit it.  Just don't ask me the implications

There's no way I can use Kotlin without editing in some form. If I set up another repositories section, that seems to "block out" the one in buildscript and stops forge from downloading.

This may help https://shadowfacts.net/forge/2016/08/06/kotlin-and-forge/