Fabric Loader 1.16.9 on 1.21.3 - Duplicate ASM Error

[andy3471]

I've tried creating a new modpack using the modpack creator for version 1.21.3.

If I add faboric-loader-0.16.9 from the Frabic Maven, but make no other changed, I get the following error when launching the modpack:

Exception in thread "main" java.lang.ExceptionInInitializerError
	at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)
Caused by: java.lang.IllegalStateException: duplicate ASM classes found on classpath: jar:file:/D:/MEGA/360NoHope/NoHopeLauncherClient/.modpacks/staging/launcher/libraries/org/ow2/asm/asm/9.7.1/asm-9.7.1.jar!/org/objectweb/asm/ClassReader.class, jar:file:/D:/MEGA/360NoHope/NoHopeLauncherClient/.modpacks/staging/launcher/libraries/org/ow2/asm/asm/9.3/asm-9.3.jar!/org/objectweb/asm/ClassReader.class
	at net.fabricmc.loader.impl.util.LoaderUtil.verifyClasspath(LoaderUtil.java:83)
	at net.fabricmc.loader.impl.launch.knot.Knot.<clinit>(Knot.java:345)
	... 1 more
Process ended with code: 1

It seems to work fine with 0.16.1 though.

It seems to extract two verisons of the ASM library to my .modpacks/staging/launcher/libraries/org/ow2/asm, 9.7.1 and 9.3. If I clear down the .modpack folder, it seems to extract again

Any ideas?

[hedgehog1029]

looks like Fabric added this check in 0.16.2: FabricMC/fabric-loader#965

Sounds like the launcher is currently not overwriting game libraries - I think generally it just concats all the library lists together. Will look into this.

[Blarnix]

Any fix or update on this?

[hedgehog1029]

Fixed in 950ad3d, libraries should now be deduplicated correctly.