Hello,

 

I have been trying to update my forge version from 1.8 and i have only been getting exceptions.

 

I tried downloading a fresh dev kit and i still get this error:

 

This mapping 'snapshot_20151122' was designed for MC 1.8! Use at your own peril.
#################################################
         ForgeGradle 2.1-SNAPSHOT-9e8f067        
  https://github.com/MinecraftForge/ForgeGradle  
#################################################
               Powered by MCP unknown               
             http://modcoderpack.com             
         by: Searge, ProfMobius, Fesh0r,         
         R4wk, ZeuX, IngisKahn, bspkrs           
#################################################
:deobfCompileDummyTask
:deobfProvidedDummyTask
:getVersionJson
:extractUserdev
Download http://files.minecraftforge.net/maven/net/minecraftforge/forge/1.8.8-11.15.0.1655/forge-1.8.8-11.15.0.1655.pom
Download http://files.minecraftforge.net/maven/net/minecraftforge/forge/1.8.8-11.15.0.1655/forge-1.8.8-11.15.0.1655-userdev.jar
:extractDependencyATs SKIPPED
:extractMcpData
Download http://files.minecraftforge.net/maven/de/oceanlabs/mcp/mcp/1.8.8/mcp-1.8.8-srg.zip
:extractMcpMappings
Download http://files.minecraftforge.net/maven/de/oceanlabs/mcp/mcp_snapshot/20151122-1.8/mcp_snapshot-20151122-1.8.zip
:genSrgs
:downloadClient
:downloadServer
:splitServerJar
:mergeJars
:deobfMcSRG
Applying SpecialSource...
Applying Exceptor...
:decompileMc
Download https://libraries.minecraft.net/com/mojang/realms/1.7.39/realms-1.7.39.pom
Download https://libraries.minecraft.net/com/mojang/realms/1.7.39/realms-1.7.39.jar
:decompileMc FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':decompileMc'.
> GC overhead limit exceeded

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 4 mins 31.736 secs

ForgeGradle for 1.8.8+ requires at least 2 GB of memory to decompile Minecraft. I believe this is due to Mojang's obfuscation process leaving generics intact instead of stripping them.

 

This tutorial explains how to give ForgeGradle more memory.

 

Side note: Why are you using 1.8.8? It's been superseded by 1.8.9.

Thanks, I will give that a go. I did try using 1.8.9 but that didn't work so then I tried 1.8.8 to see if that would work.