RuntimeError: Failed to acquire interface

lilleyse commented 1 year ago

If you try running usdrt-test on Linux you'll see the error:

2022-12-16 19:35:33 [49,101ms] [Error] [carb.scripting-python.plugin] RuntimeError: Failed to acquire interface: cesium::omniverse::ICesiumOmniverseInterface (pluginName: nullptr)

At:
  /home/slilley/Code/cesium-omniverse/exts/cesium.omniverse/cesium/omniverse/extension.py(51): on_startup
  /home/slilley/.local/share/ov/pkg/deps/82b461274b877b7d5e1a405066cfd47a/kernel/py/omni/ext/_impl/_internal.py(148): _startup_ext
  /home/slilley/.local/share/ov/pkg/deps/82b461274b877b7d5e1a405066cfd47a/kernel/py/carb/profiler/__init__.py(81): wrapper
  /home/slilley/.local/share/ov/pkg/deps/82b461274b877b7d5e1a405066cfd47a/kernel/py/omni/ext/_impl/_internal.py(197): startup
  /home/slilley/.local/share/ov/pkg/deps/82b461274b877b7d5e1a405066cfd47a/kernel/py/omni/ext/_impl/_internal.py(280): startup_extension
  PythonExtension.cpp::startup()(2): <module>

2022-12-16 19:35:33 [49,101ms] [Error] [omni.ext.plugin] [ext: cesium.omniverse-0.0.0] Failed to startup python extension.

This can be reproduced on main as well by just linking usdrt in src/core/CMakeLists.txt

Some observations so far:

The libusdrt.scenegraph.plugin.so file that ships with kit is significantly smaller than the libusdrt.scenegraph.plugin.so that ships with packman. This is not true for Windows.
usdrt is an Omniverse Native Interface but out plugin is Carbonite Interface. Normally Carbonite interfaces can declare dependencies on other Carbonite Interfaces but I'm not sure if Carbonite can declare dependencies on Omniverse Native Interfaces.

There's a note in the Carbonite Interface doc that could be relevant.

/// Note that because of some dynamic linking behavior on Linux, it is possible that on
/// unload this module could be shutdown but not actually unloaded from memory.  This would
/// prevent any global variables from being reset or cleaned up during C++ static
/// deinitialization.  However, if the plugin were loaded into the process again later,
/// C++ static initialization would not occur since the module was not previously unloaded.
/// Thus it is important to perform any and all global and static cleanup explicitly here.

lilleyse commented 1 year ago

The libusdrt.scenegraph.plugin.so file that ships with kit is significantly smaller than the libusdrt.scenegraph.plugin.so that ships with packman. This is not true for Windows.

I tried linking to the version that ships with kit but it didn't work.

For future reference here's the CMake change:

# cmake-format: off
add_prebuilt_project(
    RELEASE_INCLUDE_DIR
        "${KIT_SDK_ROOT}/extscore/usdrt.scenegraph/include"
    DEBUG_INCLUDE_DIR
        "${KIT_SDK_ROOT}/extscore/usdrt.scenegraph/include"
    RELEASE_LIBRARY_DIR
        "${KIT_SDK_ROOT}/extscore/usdrt.scenegraph/plugins"
    DEBUG_LIBRARY_DIR
        "${KIT_SDK_ROOT}/extscore/usdrt.scenegraph/plugins"
    RELEASE_LIBRARIES
        usdrt.scenegraph.plugin
    DEBUG_LIBRARIES
        usdrt.scenegraph.plugin
    TARGET_NAMES
        usdrt
)
# cmake-format: on

lilleyse commented 1 year ago

Same problem in Kit 104.2

lilleyse commented 1 year ago

This was fixed in https://github.com/CesiumGS/cesium-omniverse/pull/169. I was able to link to carb.flatcache.plugin directly since we no longer have any dependency on usdrt.

Texture loading is still broken on Linux, but that will be a separate issue.

CesiumGS / cesium-omniverse

RuntimeError: Failed to acquire interface #94