[HYDRA-1950] Crash when unloading/reloading Maya Hydra plugin

[danknowlton-apple]

Describe the bug
This crash has been at least occurring for all of the 2026 releases (including 2026.2, but probably also in earlier releases).
Crash occurs when loading the Maya Hydra plugin, unloading, and then reloading the plugin.

Seems to be caused by the TF_DEBUG symbols being registered multiple times due to the re-load.

Traceback

------------------------------- Maya terminated --------------------------------
Maya crashed. FATAL ERROR: [TF_DEBUG_ENVIRONMENT_SYMBOL] multiple debug symbol definitions for 'MAYAHYDRALIB_RENDEROVERRIDE_DEFAULT_LIGHTING'. This is usually due to software misconfiguration, such as multiple versions of the same shared library loaded simultaneously in the process. Please check your build configuration.
in _Register at line 122 of /Volumes/DATA/local/S/jenkins/workspace/ECP/ecg-usd-build/ecg-usd-full-python3.11-osx/ecg-usd-build/usd/pxr/base/tf/debug.cpp
writing crash report to [ theta.local:/var/folders/8k/kd1nc9d904n1hpp457tbmh180000gn/T//st_Maya.46264 ] ... done.
--------------------------------------------------------------------------------
zsh: abort   Maya

Steps to reproduce
Steps to reproduce the behavior:

1. Load Maya
2. Open the Plug-in Manager and load the Maya Hydra plugin (mayaHydra.bundle)
3. Unload the Maya Hydra plugin
4. Reload the Maya Hydra plugin again
5. Crash

Expected behavior
Maya should not hard-crash and potentially result in lost work.

Specs (if applicable):

• MacOS 26
• Using the Maya Hydra bundled with Maya 2026/2026.2
• Using the default USD 24.11 config

[santosd]

Hi @danknowlton-apple thank you for reporting this issue. We will take a look. However, I was wondering if there is any specific reason for the unload and reload of the plugin?

[danknowlton-apple]

Thanks!
No, there isn't a specific workflow that needs to unload/reload so it can likely be avoided in most cases. One of our team-members just discovered the crash while testing out the plugin.

[santosd]

Sounds good, thank you.