Bump usd-core dependency to 26.05 to fix USD physics crash

isaaclab.bat

@@ -41,6 +41,19 @@ if exist "%ISAACLAB_PATH%\_isaac_sim\" (
     )
 )
 
+rem If omni.usd.libs is present, prepend it to PYTHONPATH and its bin\ to PATH
+rem so its patched pxr is found before usd-core's pxr and the native USD shared
+rem libraries are resolvable, resolving TfType::AddAlias conflicts.
+rem
+rem omni.usd.libs\pxr\ is a namespace package (no __init__.py), but Python
+rem prefers a regular package (with __init__.py) over a namespace package
+rem regardless of sys.path order.  Write a minimal __init__.py to promote it
+rem to a regular package so the PYTHONPATH prepend actually takes effect.
+for /f "delims=" %%d in ('"%python_exe%" "%ISAACLAB_PATH%\tools\setup_usd_libs.py" 2^>nul') do (
+    set "PYTHONPATH=%%d;!PYTHONPATH!"
+    set "PATH=%%d\bin;!PATH!"
+)
+
 rem Execute CLI.
 "%python_exe%" -c "from isaaclab.cli import cli; cli()" %*
 

isaaclab.sh

@@ -61,5 +61,23 @@ if [ -d "$ISAACLAB_PATH/_isaac_sim" ]; then
     fi
 fi
 
+# If omni.usd.libs is present, prepend it to PYTHONPATH and its bin/ to
+# LD_LIBRARY_PATH so its patched pxr is found before usd-core's pxr and the
+# native USD shared libraries are resolvable.  This resolves TfType::AddAlias
+# conflicts when omni.usd.schema packages (ovrtx/ovphysx) are also installed.
+#
+# omni.usd.libs/pxr/ is a namespace package (no __init__.py), but Python's
+# import system always prefers a regular package (with __init__.py) over a
+# namespace package, regardless of sys.path order.  Since usd-core installs a
+# regular pxr package, prepending omni.usd.libs to PYTHONPATH alone does nothing.
+# We write a minimal __init__.py into omni.usd.libs/pxr/ to promote it to a
+# regular package, making the sys.path order actually take effect.
+_ov_usd_libs_dir=$("$python_exe" "$ISAACLAB_PATH/tools/setup_usd_libs.py" 2>/dev/null)
+if [ -n "$_ov_usd_libs_dir" ]; then
+    export PYTHONPATH="$_ov_usd_libs_dir:$PYTHONPATH"
+    export LD_LIBRARY_PATH="$_ov_usd_libs_dir/bin:$LD_LIBRARY_PATH"
+fi
+unset _ov_usd_libs_dir
+
 # Execute CLI.
 exec "$python_exe" -c "from isaaclab.cli import cli; cli()" "$@"

pyproject.toml

@@ -63,7 +63,7 @@ dependencies = [
     # OpenUSD (kit-less mode). Both packages vendor a complete ``pxr`` runtime, so
     # they must never co-install: usd-core supplies pxr where it has wheels (x86_64),
     # usd-exchange supplies it on aarch64 (where usd-core has no wheel).
-    "usd-core>=25.11,<26.0 ; platform_machine in 'x86_64 AMD64'",
+    "usd-core>=26.05,<27.0 ; platform_machine in 'x86_64 AMD64'",
     "usd-exchange>=2.2 ; platform_machine in 'aarch64 arm64'",
     # avoid broken hf-xet pre-release cached on NVIDIA Artifactory
     "hf-xet>=1.4.1,<2.0.0 ; platform_machine in 'x86_64 AMD64 aarch64 arm64'",

source/isaaclab/changelog.d/mataylor-golden-sim-usd.minor.rst

@@ -0,0 +1,5 @@
+Changed
+^^^^^^^
+
+* Bumped ``usd-core`` dependency from ``>=25.11,<26.0`` to ``>=26.05,<27.0`` on x86_64 to resolve
+  a crash in ``libusd_ms`` triggered by USD physics loading (``LoadUsdPhysicsFromRange``) for kitless runs.

source/isaaclab/test/benchmark/test_capture.py

@@ -72,7 +72,7 @@ def test_capture_versions_preserves_runtime_packages():
         StringMetadata(name="ovphysx_version", data="3.0.5"),
         StringMetadata(name="mujoco_version", data="3.8.1"),
         StringMetadata(name="cuda_bindings_version", data="12.9.4"),
-        StringMetadata(name="usd_core_version", data="25.11"),
+        StringMetadata(name="usd_core_version", data="26.05"),
         StringMetadata(name="isaaclab_release_version", data="3.0.0"),
     ]
     bm = _Bm({"VersionInfo": _Rec(MeasurementData(measurements=[], metadata=md, artefacts=[]))})
@@ -89,7 +89,7 @@ def test_capture_versions_preserves_runtime_packages():
     assert versions.ovphysx == "3.0.5"
     assert versions.mujoco == "3.8.1"
     assert versions.cuda_bindings == "12.9.4"
-    assert versions.usd_core == "25.11"
+    assert versions.usd_core == "26.05"
     assert versions.isaaclab_release == "3.0.0"
 
 

source/isaaclab/test/cli/test_source_package_metadata.py

@@ -23,16 +23,16 @@ def _repo_root() -> Path:
     raise RuntimeError("Could not find Isaac Lab repository root.")
 
 
-def test_isaaclab_usd_core_pin_stays_on_isaacsim_compatible_usd25_abi():
-    """The kit-less USD package must stay on the Isaac Sim compatible USD 25 ABI."""
+def test_isaaclab_usd_core_pin_stays_on_isaacsim_compatible_usd26_abi():
+    """The kit-less USD package must stay on the Isaac Sim compatible USD 26 ABI."""
     with (_repo_root() / "pyproject.toml").open("rb") as f:
         pyproject = tomllib.load(f)
 
     usd_core_dependencies = [
         dependency for dependency in pyproject["project"]["dependencies"] if dependency.startswith("usd-core")
     ]
 
-    assert usd_core_dependencies == ["usd-core>=25.11,<26.0 ; platform_machine in 'x86_64 AMD64'"]
+    assert usd_core_dependencies == ["usd-core>=26.05,<27.0 ; platform_machine in 'x86_64 AMD64'"]
 
 
 def test_isaaclab_standalone_usd_providers_are_platform_disjoint():

tools/setup_usd_libs.py

@@ -0,0 +1,28 @@
+# Copyright (c) 2022-2026, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+"""Locate the omni.usd.libs extension and promote its pxr package to a regular package.
+
+Prints the resolved directory path to stdout (empty string if not found).
+Called by isaaclab.sh / isaaclab.bat before launching the CLI so that the
+shell can prepend the path to PYTHONPATH / LD_LIBRARY_PATH / PATH.
+"""
+
+import contextlib
+import glob
+import os
+
+extscache = os.path.join(os.environ.get("ISAACLAB_PATH", ""), "_isaac_sim", "extscache")
+candidates = sorted(glob.glob(os.path.join(extscache, "omni.usd.libs-*")))
+if not candidates:
+    print("", end="")
+else:
+    usd_libs_dir = candidates[-1]
+    pxr_dir = os.path.join(usd_libs_dir, "pxr")
+    init_py = os.path.join(pxr_dir, "__init__.py")
+    if os.path.isdir(pxr_dir) and not os.path.isfile(init_py):
+        with contextlib.suppress(OSError):
+            open(init_py, "w").close()
+    print(usd_libs_dir, end="")