org.reflections won't work

[hexadecimal233]

Describe the bug

org.reflections won't work

Steps to reproduce

1. Install this mod: MC-Reflections-1.0-SNAPSHOT.jar.zip (Code)
2. Run using connector
3. Error pops up in console. Reflections won't work.

Expected

A "Hello world" will be printed to console.

Logs

[11Aug2023 22:50:24.150] [Render thread/WARN] [org.reflections.Reflections/]: could not create Vfs.Dir from url. ignoring the exception and continuing
org.reflections.ReflectionsException: Could not open url connection
	at org.reflections.vfs.JarInputDir$1.<init>(JarInputDir.java:31) ~[MC-Reflections-1.0-SNAPSHOT$reflections-0.10.2_mapped_srg_1.20.1.jar%23177!/:?]
	at org.reflections.vfs.JarInputDir.lambda$getFiles$0(JarInputDir.java:28) ~[MC-Reflections-1.0-SNAPSHOT$reflections-0.10.2_mapped_srg_1.20.1.jar%23177!/:?]
	at org.reflections.Reflections.lambda$scan$2(Reflections.java:177) ~[MC-Reflections-1.0-SNAPSHOT$reflections-0.10.2_mapped_srg_1.20.1.jar%23177!/:?]
	at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183) ~[?:?]
	at java.util.HashMap$KeySpliterator.forEachRemaining(HashMap.java:1707) ~[?:?]
	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[?:?]
	at java.util.stream.ForEachOps$ForEachTask.compute(ForEachOps.java:290) ~[?:?]
	at java.util.concurrent.CountedCompleter.exec(CountedCompleter.java:754) ~[?:?]
	at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373) ~[?:?]
	at java.util.concurrent.ForkJoinTask.invoke(ForkJoinTask.java:686) ~[?:?]
	at java.util.stream.ForEachOps$ForEachOp.evaluateParallel(ForEachOps.java:159) ~[?:?]
	at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateParallel(ForEachOps.java:173) ~[?:?]
	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:233) ~[?:?]
	at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596) ~[?:?]
	at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:765) ~[?:?]
	at org.reflections.Reflections.scan(Reflections.java:173) ~[MC-Reflections-1.0-SNAPSHOT$reflections-0.10.2_mapped_srg_1.20.1.jar%23177!/:?]
	at org.reflections.Reflections.<init>(Reflections.java:126) ~[MC-Reflections-1.0-SNAPSHOT$reflections-0.10.2_mapped_srg_1.20.1.jar%23177!/:?]
	at org.reflections.Reflections.<init>(Reflections.java:159) ~[MC-Reflections-1.0-SNAPSHOT$reflections-0.10.2_mapped_srg_1.20.1.jar%23177!/:?]
	at org.reflections.Reflections.<init>(Reflections.java:151) ~[MC-Reflections-1.0-SNAPSHOT$reflections-0.10.2_mapped_srg_1.20.1.jar%23177!/:?]
	at me.chirin.mcreflections.ReflectTest.init(ReflectTest.java:14) ~[MC-Reflections-1.0-SNAPSHOT_mapped_srg_1.20.1.jar%23176!/:?]
	at me.chirin.mcreflections.MCReflections.onInitialize(MCReflections.java:8) ~[MC-Reflections-1.0-SNAPSHOT_mapped_srg_1.20.1.jar%23176!/:?]
	at net.fabricmc.loader.impl.entrypoint.EntrypointUtils.invoke0(EntrypointUtils.java:47) ~[Connector-1.0.0-beta.3+1.20.1-full.jar%23158!/:?]
	at net.fabricmc.loader.impl.entrypoint.EntrypointUtils.invoke(EntrypointUtils.java:35) ~[Connector-1.0.0-beta.3+1.20.1-full.jar%23158!/:?]
	at dev.su5ed.sinytra.connector.mod.ConnectorLoader.load(ConnectorLoader.java:52) ~[Connector-1.0.0-beta.3+1.20.1-mod.jar%23161!/:?]
	at net.minecraft.client.Minecraft.handler$zzf000$earlyInit(Minecraft.java:2930) ~[client-1.20.1-20230612.114412-srg.jar%23163!/:?]
	at net.minecraft.client.Minecraft.<init>(Minecraft.java:424) ~[client-1.20.1-20230612.114412-srg.jar%23163!/:?]
	at net.minecraft.client.main.Main.main(Main.java:182) ~[minecraft-1.20.1-client.jar:?]
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[?:?]
	at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
	at java.lang.reflect.Method.invoke(Method.java:568) ~[?:?]
	at net.minecraftforge.fml.loading.targets.CommonLaunchHandler.runTarget(CommonLaunchHandler.java:111) ~[fmlloader-1.20.1-47.1.43.jar:?]
	at net.minecraftforge.fml.loading.targets.CommonLaunchHandler.clientService(CommonLaunchHandler.java:99) ~[fmlloader-1.20.1-47.1.43.jar:?]
	at net.minecraftforge.fml.loading.targets.CommonClientLaunchHandler.lambda$makeService$0(CommonClientLaunchHandler.java:25) ~[fmlloader-1.20.1-47.1.43.jar:?]
	at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:30) ~[modlauncher-10.0.9.jar:?]
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:53) ~[modlauncher-10.0.9.jar:?]
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:71) ~[modlauncher-10.0.9.jar:?]
	at cpw.mods.modlauncher.Launcher.run(Launcher.java:108) ~[modlauncher-10.0.9.jar:?]
	at cpw.mods.modlauncher.Launcher.main(Launcher.java:78) ~[modlauncher-10.0.9.jar:?]
	at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26) ~[modlauncher-10.0.9.jar:?]
	at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23) ~[modlauncher-10.0.9.jar:?]
	at cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:141) ~[bootstraplauncher-1.1.2.jar:?]
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[?:?]
	at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
	at java.lang.reflect.Method.invoke(Method.java:568) ~[?:?]
	at io.github.zekerzhayard.forgewrapper.installer.Main.main(Main.java:57) ~[?:?]
	at org.prismlauncher.launcher.impl.StandardLauncher.launch(StandardLauncher.java:88) ~[?:?]
	at org.prismlauncher.EntryPoint.listen(EntryPoint.java:126) ~[?:?]
	at org.prismlauncher.EntryPoint.main(EntryPoint.java:71) ~[?:?]
Caused by: java.nio.file.NoSuchFileException: /
	at jdk.nio.zipfs.ZipFileSystem.newByteChannel(ZipFileSystem.java:974) ~[jdk.zipfs:?]
	at jdk.nio.zipfs.ZipPath.newByteChannel(ZipPath.java:864) ~[jdk.zipfs:?]
	at jdk.nio.zipfs.ZipFileSystemProvider.newByteChannel(ZipFileSystemProvider.java:238) ~[jdk.zipfs:?]
	at java.nio.file.Files.newByteChannel(Files.java:380) ~[?:?]
	at java.nio.file.Files.newByteChannel(Files.java:432) ~[?:?]
	at cpw.mods.niofs.union.UnionFileSystem.byteChannel(UnionFileSystem.java:348) ~[securejarhandler-2.1.10.jar:?]
	at java.util.Optional.map(Optional.java:260) ~[?:?]
	at cpw.mods.niofs.union.UnionFileSystem.newReadByteChannel(UnionFileSystem.java:339) ~[securejarhandler-2.1.10.jar:?]
	at cpw.mods.niofs.union.UnionFileSystemProvider.newByteChannel(UnionFileSystemProvider.java:149) ~[securejarhandler-2.1.10.jar:?]
	at java.nio.file.Files.newByteChannel(Files.java:380) ~[?:?]
	at java.nio.file.Files.newByteChannel(Files.java:432) ~[?:?]
	at java.nio.file.Files.readAllBytes(Files.java:3288) ~[?:?]
	at cpw.mods.niofs.union.UnionFileSystem.buildInputStream(UnionFileSystem.java:70) ~[securejarhandler-2.1.10.jar:?]
	at cpw.mods.niofs.union.UnionPath.buildInputStream(UnionPath.java:331) ~[securejarhandler-2.1.10.jar:?]
	at cpw.mods.cl.UnionURLStreamHandler.lambda$inputStreamFunction$0(UnionURLStreamHandler.java:25) ~[securejarhandler-2.1.10.jar:?]
	at cpw.mods.cl.ModularURLHandler$FunctionURLConnection.getInputStream(ModularURLHandler.java:65) ~[securejarhandler-2.1.10.jar:?]
	at org.reflections.vfs.JarInputDir$1.<init>(JarInputDir.java:30) ~[MC-Reflections-1.0-SNAPSHOT$reflections-0.10.2_mapped_srg_1.20.1.jar%23177!/:?]
	... 49 more
[11Aug2023 22:50:24.156] [Render thread/INFO] [org.reflections.Reflections/]: Reflections took 15 ms to scan 1 urls, producing 0 keys and 0 values

Additional context

No response

[Su5eD]

The issue here seems to be caused by the Reflections library trying to open an input stream on the root URL of a jar, which the union file system doesn't support. It could a bug / unimplemented feature, as trying the same on a real directory path works fine.

All resource location URIs in Forge use the union file system by default, so to get it to work you'd need to explicitly pass in one that points to the outer file system.

[Su5eD]

I fixed Forgified Fabric Loader to provide the real file path from the ModOrigin inside the mod container, achieving parity with upstream. You can now use that to get the file URI to pass into reflections. Hopefully that helps.