Cleanroom and Curseforge modpack? (Nomi CEu)

[lhancewong]

Hello everyone,

I am trying to get a Nomifactory Ceu server running via the Cleanroom method described here. Is it possible to combine auto curseforge with a cleanroom forge file? I tried lo

I tried something like this but it didn't work.

services:
  mc:
    image: itzg/minecraft-server:java21
    tty: true
    stdin_open: true
    ports:
      - "25590:25565"
    environment:
      EULA: "TRUE"
      FORGE_INSTALLER_URL: https://github.com/CleanroomMC/Cleanroom/releases/download/0.4.4-alpha/cleanroom-0.4.4-alpha-installer.jar
      # Auto curseforge stuff
      MODPACK_PLATFORM: AUTO_CURSEFORGE
      CF_API_KEY: ${CF_API_KEY}
      CF_PAGE_URL: https://www.curseforge.com/minecraft/modpacks/nomi-ceu
      CURSEFORGE_FILES: |
        https://www.curseforge.com/minecraft/mc-mods/scalar-legacy/files/6842491
        https://www.curseforge.com/minecraft/mc-mods/fugue/files/7355882
      MEMORY: 12G
      CREATE_CONSOLE_IN_PIPE: "true"
    volumes:
      - ./mc-data:/data
volumes:
  mc-data:

I followed the FORGE_INSTALLER_URL field for cleanroom but i got a warning when using both MODPACK_PLATFORM: AUTO_CURSEFORGE and TYPE: FORGE. So I stuck with auto curseforge.

these are some of the logs. not sure how to expose the full logs. my apologies

mc-1  | [mc-image-helper] 15:35:20.486 INFO  : Downloaded mod file mods/PackagedAuto-1.12.2-1.0.23.72.jar
mc-1  | [mc-image-helper] 15:35:20.590 INFO  : Downloaded mod file mods/PackagedExCrafting-1.12.2-1.0.3.33.jar
mc-1  | [mc-image-helper] 15:35:20.745 INFO  : Downloaded mod file mods/collective-1.12.2-3.0.jar
mc-1  | [mc-image-helper] 15:35:20.809 INFO  : Downloaded mod file mods/spark-forge1122.jar
mc-1  | [mc-image-helper] 15:35:20.973 INFO  : Downloaded mod file mods/FTBBackups-1.1.0.1.jar
mc-1  | [mc-image-helper] 15:35:20.983 INFO  : Downloaded mod file mods/Bountiful-2.2.2.jar
mc-1  | [mc-image-helper] 15:35:21.174 INFO  : Downloaded mod file mods/framedcompactdrawers-1.2.7.jar
mc-1  | [mc-image-helper] 15:35:21.238 INFO  : Downloaded mod file mods/MoreFurnaces-Nomifactory-Edition-1.12.2-1.11.0.jar
mc-1  | [mc-image-helper] 15:35:21.263 INFO  : Downloaded mod file mods/advsolars-1.0.jar
mc-1  | [mc-image-helper] 15:35:21.277 INFO  : Downloaded mod file mods/supersoundmuffler-revived_1.12.2_1.0.2.10.jar
mc-1  | [mc-image-helper] 15:35:21.453 INFO  : Downloaded mod file mods/!mixinbooter-10.7.jar
mc-1  | [mc-image-helper] 15:35:21.498 INFO  : Downloaded mod file mods/DimensionalEdibles-1.12.2-1.6.4.jar
mc-1  | [mc-image-helper] 15:35:21.685 INFO  : Downloaded mod file mods/loliasm-5.30.jar
mc-1  | [mc-image-helper] 15:35:21.708 INFO  : Downloaded mod file mods/Forgelin-Continuous-2.2.21.0.jar
mc-1  | [mc-image-helper] 15:35:21.710 INFO  : Downloaded mod file mods/extendedcrafting-nomifactory-edition-1.7.0.7.jar
mc-1  | [mc-image-helper] 15:35:21.748 INFO  : Downloaded mod file mods/dynamistics-1.0.2.jar
mc-1  | [mc-image-helper] 15:35:21.923 INFO  : Downloaded mod file mods/uberconduitprobe-1.0.3.jar
mc-1  | [mc-image-helper] 15:35:21.969 INFO  : Downloaded mod file mods/oauth-1.06.4.jar
mc-1  | [mc-image-helper] 15:35:21.975 INFO  : Downloaded mod file mods/DefaultWorldGenerator-port-1.12-2.3.1.jar
mc-1  | [mc-image-helper] 15:35:22.397 INFO  : Downloaded mod file mods/ae2-uel-v0.56.5.jar
mc-1  | [mc-image-helper] 15:35:22.472 INFO  : Downloaded mod file mods/modularui-3.0.4.jar
mc-1  | [mc-image-helper] 15:35:22.623 INFO  : Downloaded mod file mods/BetterQuestingUnofficial-4.2.2.jar
mc-1  | [mc-image-helper] 15:35:22.655 INFO  : Downloaded mod file mods/bogosorter-1.5.0.jar
mc-1  | [mc-image-helper] 15:35:22.862 INFO  : Downloaded mod file mods/gregtech-1.12.2-2.8.10-beta.jar
mc-1  | [mc-image-helper] 15:35:22.869 INFO  : Downloaded mod file mods/ULVCovers-1.12.2-2.8.0.jar
mc-1  | [mc-image-helper] 15:35:22.889 INFO  : Downloaded mod file mods/HadEnoughItems_1.12.2-4.29.14.jar
mc-1  | [mc-image-helper] 15:35:23.015 INFO  : Downloaded mod file mods/GregicalityMultiblocks-1.2.11.jar
mc-1  | [mc-image-helper] 15:35:23.120 INFO  : Downloaded mod file mods/findme-1.12.2-1.0.0.jar
mc-1  | [mc-image-helper] 15:35:23.147 INFO  : Downloaded mod file mods/groovyscript-1.3.3.jar
mc-1  | [mc-image-helper] 15:35:23.306 INFO  : Downloaded mod file mods/DeepMobEvolution-1.12.2-1.2.3.jar
mc-1  | [mc-image-helper] 15:35:23.313 INFO  : Downloaded mod file mods/CraftingTweaks_1.12.2-9.0.1.jar
mc-1  | [mc-image-helper] 15:35:23.342 INFO  : Downloaded mod file mods/PackagedDraconic-1.12.2-1.0.4.24.jar
mc-1  | [mc-image-helper] 15:35:23.387 INFO  : Downloaded mod file mods/UniversalTweaks-1.12.2-1.17.0.jar
mc-1  | [mc-image-helper] 15:35:23.570 INFO  : Downloaded mod file mods/gregtech-drawers-1.12.2-1.0.7.jar
mc-1  | [mc-image-helper] 15:35:23.588 INFO  : Downloaded mod file mods/nonetherportals-1.1.0.jar
mc-1  | [mc-image-helper] 15:35:23.703 INFO  : Downloaded mod file mods/vintagefix-0.6.2.jar
mc-1  | [mc-image-helper] 15:35:23.804 INFO  : Downloaded mod file mods/!configanytime-3.0.jar
mc-1  | [mc-image-helper] 15:35:23.804 INFO  : Downloaded mod file mods/!Red-Core-MC-1.8-1.12-0.6.jar
mc-1  | [mc-image-helper] 15:35:24.000 INFO  : Downloaded mod file mods/serializationisbad-1.5.2.jar
mc-1  | [mc-image-helper] 15:35:24.020 INFO  : Downloaded mod file mods/Alfheim-1.6.jar
mc-1  | [mc-image-helper] 15:35:24.278 INFO  : Downloaded mod file mods/betterp2p-1.12.2-1.3.2.jar
mc-1  | [mc-image-helper] 15:35:24.285 INFO  : Downloaded mod file mods/NomiLabs-0.17.14.jar
mc-1  | [mc-image-helper] 15:35:24.427 INFO  : Downloaded mod file mods/visualores-0.2.6.jar
mc-1  | [mc-image-helper] 15:35:24.473 INFO  : Downloaded mod file mods/RealBench-Nomi-CEu-1.0.4.jar
mc-1  | [mc-image-helper] 15:35:24.477 INFO  : Downloaded mod file mods/ae2stuff-1.12.2-0.10.jar
mc-1  | [mc-image-helper] 15:35:24.493 INFO  : Downloaded mod file mods/TheOneSmeagle-1.12-1.1.5.jar
mc-1  | [mc-image-helper] 15:35:24.559 INFO  : Downloaded mod file mods/nae2-1.6.4.jar
mc-1  | [mc-image-helper] 15:35:24.711 INFO  : Downloaded mod file mods/AE2CT-Legacy-0.1.2.jar
mc-1  | [mc-image-helper] 15:35:24.757 INFO  : Downloaded mod file mods/LibrarianLib-Continuous-1.12.2-4.22-2.0-3.jar
mc-1  | [mc-image-helper] 15:35:25.224 INFO  : Downloaded mod file mods/sussypatches-1.9.2.jar
mc-1  | [mc-image-helper] 15:35:26.167 INFO  : Downloading Forge installer 14.23.5.2860 for Minecraft 1.12.2
mc-1  | [mc-image-helper] 15:35:28.499 INFO  : Running Forge 14.23.5.2860 installer for Minecraft 1.12.2. This might take a while...
mc-1  | [mc-image-helper] 15:35:35.868 INFO  : Downloaded mod file mods/+Fugue-0.22.6.jar
mc-1  | [mc-image-helper] 15:35:36.394 INFO  : Downloaded mod file mods/Scalar Legacy-1.0.1.jar
mc-1  | [init] Copying any mods from /mods to /data/mods
mc-1  | [init] Copying any configs from /config to /data/config
mc-1  | [init] Creating server properties in /data/server.properties
mc-1  | [init] Enabling whitelist functionality
mc-1  | [mc-image-helper] 15:35:39.132 INFO  : Created/updated 5 properties in /data/server.properties
mc-1  | [init] Setting initial memory to 12G and max to 12G
mc-1  | [init] Starting the Minecraft server...
mc-1  | A problem occurred running the Server launcher.java.lang.reflect.InvocationTargetException
mc-1  |         at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Unknown Source)
mc-1  |         at java.base/java.lang.reflect.Method.invoke(Unknown Source)
mc-1  |         at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.java:70)
mc-1  |         at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:34)
mc-1  | Caused by: java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader (jdk.internal.loader.ClassLoaders$AppClassLoader and java.net.URLClassLoader are in module java.base of loader 'bootstrap')
mc-1  |         at net.minecraft.launchwrapper.Launch.<init>(Launch.java:34)
mc-1  |         at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
mc-1  |         ... 4 more
mc-1  | 2026-04-21T15:35:43.747Z        WARN    mc-server-runner        Minecraft server failed. Inspect logs above for errors that indicate cause. DO NOT report this line as an error.        {"exitCode": 1}
mc-1  | 2026-04-21T15:35:43.747Z        INFO    mc-server-runner        Done
mc-1 exited with code 1

Seeing this mc-1 | [mc-image-helper] 15:35:28.499 INFO : Running Forge 14.23.5.2860 installer for Minecraft 1.12.2. This might take a while... makes me think that cleanroom isnt being used. And since the compose is using java 21, i feel that will make the server fail to run..

Regardless, is cleanroom and a curseforge modpack possible? :0

Thanks,

[cookesan]

The log shows that Cleanroom is not the loader being used in that compose file.

MODPACK_PLATFORM: AUTO_CURSEFORGE lets the CurseForge modpack flow own the mod loader installation. In your log it downloads the modpack and then installs Forge 14.23.5.2860:

Downloading Forge installer 14.23.5.2860 for Minecraft 1.12.2
Running Forge 14.23.5.2860 installer for Minecraft 1.12.2

That means the FORGE_INSTALLER_URL path is not winning here. The documented Cleanroom setup is:

environment:
  TYPE: FORGE
  FORGE_INSTALLER_URL: https://github.com/CleanroomMC/Cleanroom/releases/download/.../cleanroom-...-installer.jar

Auto CurseForge can install the loader declared by the modpack, and it has CF_MOD_LOADER_VERSION for overriding a loader version, but I do not see a documented path that combines Auto CurseForge managed modpack loader installation with an arbitrary Cleanroom installer.

You probably have two practical paths:

1. Use MODPACK_PLATFORM: AUTO_CURSEFORGE with the normal Forge loader. Since this is Minecraft 1.12.2 / old Forge, use a Java 8 image; the URLClassLoader ClassCastException is the usual "old Forge on too-new Java" failure.
2. If you specifically need Cleanroom, use the documented TYPE: FORGE + FORGE_INSTALLER_URL Cleanroom setup and handle the modpack files separately/manual from the automatic CurseForge loader flow.

I would not set this up as both Auto CurseForge and custom Cleanroom installer at the same time, because those two modes are trying to control the same loader installation step.

[lhancewong]

Thanks for the reply,

After your advice I came up with this and the sever ran.

services:
  mc:
    image: itzg/minecraft-server:java21
    tty: true
    stdin_open: true
    ports:
      - "25590:25565"
    environment:
      EULA: "TRUE"
# Cleanroom
      TYPE: FORGE
      FORGE_INSTALLER_URL: https://github.com/CleanroomMC/Cleanroom/releases/download/0.4.4-alpha/cleanroom-0.4.4-alpha-installer.jar
# Modpack
      GENERIC_PACK: /modpacks/nomi-ceu-1.7.7-server.zip
      MODS: |
        https://github.com/CleanroomMC/Fugue/releases/download/0.22.6/+Fugue-0.22.6.jar
        https://github.com/CleanroomMC/Scalar/releases/download/2.11.1/scalar-1.12.2-2.11.1.jar
# Configure server
      MEMORY: 12G
      USE_MEOWICE_FLAGS: true
      CREATE_CONSOLE_IN_PIPE: "true"
    volumes:
      - ./modpacks:/modpacks:ro
      - ./mc-data:/data
volumes:
  mc-data:

Again, I couldn't get the full logs but this part makes me believe that it is using the cleanroom forge.

mc-1  | [init] Running as uid=1000 gid=1000 with /data as 'drwxrwxr-x. 2 1000 1000 6 Apr 22 00:59 /data'
mc-1  | [init] Image info: buildtime=2026-04-16T18:42:03.172Z,version=java21,revision=97407c672fccc431e5eca6d4c1d008972b5f230f
mc-1  | [init] Resolving type given FORGE
mc-1  | [mc-image-helper] 00:59:42.708 INFO  : Running cleanroom 0.4.4-alpha installer for Minecraft 1.12.2. This might take a while...
mc-1  | [mc-image-helper] 00:59:54.903 INFO  : Downloaded /data/mods/+Fugue-0.22.6.jar from https://github.com/CleanroomMC/Fugue/releases/download/0.22.6/+Fugue-0.22.6.jar
mc-1  | [mc-image-helper] 00:59:55.801 INFO  : Downloaded /data/mods/scalar-1.12.2-2.11.1.jar from https://github.com/CleanroomMC/Scalar/releases/download/2.11.1/scalar-1.12.2-2.11.1.jar
mc-1  | [init] Checking if generic packs are up to date
mc-1  | [init] Generic pack(s) are out of date. Re-applying...
mc-1  | [init] Writing generic pack manifest ... 
mc-1  | [init] Applying generic pack ...
mc-1  | [init] Saving generic pack(s) checksum
mc-1  | [init] Copying any mods from /mods to /data/mods
mc-1  | [init] Copying any configs from /config to /data/config
mc-1  | [init] Enabling whitelist functionality
mc-1  | [mc-image-helper] 01:00:05.055 INFO  : Created/updated 5 properties in /data/server.properties

Haven't tried connecting yet, but im pretty sure this is working now. Thanks!

[cookesan]

Great news. Enjoy :)