ModuleMetadata::Dump() produces no output on Linux for Dota 2 (only filesystem_stdio attempted)

[z3nnik]

Summary

On Linux, DumpSource2-DOTA completes successfully and dumps schemas (schemas/, schemas.json), convars, and commands, but module_metadata/ is never created — no .kv3 files.

On Windows, GameTracking’s Dota 2 pipeline produces a full DumpSource2/module_metadata/ tree (client.kv3, server.kv3, particles.kv3, etc.).

Environment

Game: Dota 2 (AppID 570), ClientVersion=6840 (Jun 28 2026)
OS: Ubuntu 24.04 LTS, x86_64
Binary: DumpSource2-DOTA from GameTracking tools release tools-linux-x64.tar.gz (2026-06-27, build 5eb38ed)
Client: game/dota/bin/linuxsteamrt64/libclient.so (depot 373306)
CWD: game/bin/linuxsteamrt64/ (same layout as GameTracking dump_source2.sh)
LD_LIBRARY_PATH: linuxsteamrt64 + SDL3 (implib stub for libvideo.so only)

Steps to reproduce

1. Download Dota 2 Linux binaries (incl. libclient.so) and game/bin/linuxsteamrt64/ deps.
2. Apply implib stub for libvideo.so (as in GameTracking dump_source2.sh).
3. From game/bin/linuxsteamrt64/:

LD_LIBRARY_PATH="$(pwd):$SDL3_PATH" ./DumpSource2-DOTA /path/to/DumpSource2/output

4. Check output directory.

Expected behavior

Same as GameTracking-Dota2 on Windows:

• DumpSource2/module_metadata/client.kv3
• DumpSource2/module_metadata/server.kv3
• ~30 .kv3 files total with resource_manifests, etc.

Actual behavior

• convars.txt, commands.txt, schemas/, schemas.json — OK
• module_metadata/ — missing (directory not created)
• Log shows module metadata step starts, but only one module is processed:

[info] Dumping module metadata
[info] Dumping metadata for filesystem_stdio

• No further Dumping metadata for client / server / etc.

No warnings/errors mentioning ExtractModuleMetadata or empty module metadata.

grep 'Dumping metadata for' dumpsource2.log
# only: filesystem_stdio
find DumpSource2/module_metadata -name '*.kv3' | wc -l
# 0 (directory does not exist)

Additional context

ModuleMetadata::Dump() only creates module_metadata/ when buf is non-empty after ExtractModuleMetadata().

For filesystem_stdio, the log line appears but no .kv3 is written → buffer appears empty.

Game modules (client, server, …) are not logged at all — unclear if they are missing from Modules::allModules on Linux or skipped earlier.

Schema-related warnings during dump (unrelated to this issue):

Metadata 'MDebugSnapshotDataRenderFn' has unknown value for parser

Question

Is ExtractModuleMetadata / module_metadata KV3 export expected to work on Linux for Dota 2? If not, could this be documented? If yes, is there a known workaround (extra libs, different cwd, win64-only modules list)?

Happy to provide full dumpsource2-last.log, binary hashes, or test on a specific DumpSource2 commit.

[z3nnik]

I looked into this on a Linux host with a full app-system init (20 modules in Modules::allModules).

ExtractModuleMetadata is exported by the Linux game libraries, but it's just a stub that always returns null (verified with objdump). All 20 modules behave the same way, while schemas, convars, and commands dump successfully in the same run.

The original report also exposed a separate DumpSource2 issue: when no .kv3 files are generated, orphan cleanup tries to iterate over a non-existent module_metadata/ directory, causing the dump to terminate early. I fixed that by checking whether the directory exists before iterating and improving the handling of empty metadata.

PR: #11

Conclusion:

Full module_metadata generation on Linux isn't currently possible because Valve's Linux implementation of ExtractModuleMetadata is a stub.
The early termination is a real DumpSource2 bug and is addressed in the linked PR.