isaac-sim · hujc7 · May 15, 2026
diff --git a/source/isaaclab/changelog.d/jichuanh-pin-numpy-not-2-3-5.rst b/source/isaaclab/changelog.d/jichuanh-pin-numpy-not-2-3-5.rst
@@ -0,0 +1,10 @@
+Fixed
+^^^^^
+
+* Excluded NumPy 2.3.5 from the install constraint (``numpy>=2,!=2.3.5``). The 2.3.5
+  release ships a vendored OpenBLAS (``libscipy_openblas64_-fdde5778.so``) whose
+  ``pthread_atfork`` handler crashes inside Kit's ``libomni.platforminfo`` ``fork()``
+  during ``SimulationApp`` startup, manifesting as non-deterministic SIGSEGV in CI
+  test jobs. See `numpy#30092 <https://github.com/numpy/numpy/issues/30092>`_ and
+  ``OMPE-92261``. With this change pip resolves to NumPy 2.3.4, which ships a
+  different OpenBLAS bundle without the regression.
diff --git a/source/isaaclab/setup.py b/source/isaaclab/setup.py
@@ -18,7 +18,11 @@
 # Minimum dependencies required prior to installation
 INSTALL_REQUIRES = [
     # generic
-    "numpy>=2",
+    # !=2.3.5 dodges the broken OpenBLAS bundle (libscipy_openblas64_-fdde5778.so)
+    # whose pthread_atfork handler SIGSEGVs inside Kit's libomni.platforminfo fork()
+    # during CI startup. See numpy/numpy#30092 and OMPE-92261. The pin-pink ->
+    # pinocchio -> cmeel-boost transitive constraint already caps numpy <2.4.
+    "numpy>=2,!=2.3.5",
     "torch>=2.10",
     "onnx>=1.18.0",  # 1.16.2 throws access violation on Windows
     "prettytable==3.3.0",

diff --git a/source/isaaclab_rl/changelog.d/jichuanh-pin-numpy-not-2-3-5.rst b/source/isaaclab_rl/changelog.d/jichuanh-pin-numpy-not-2-3-5.rst
@@ -0,0 +1,6 @@
+Fixed
+^^^^^
+
+* Tightened the NumPy install constraint to ``numpy>=2,!=2.3.5`` (was unconstrained)
+  to keep the package consistent with :file:`isaaclab/setup.py` and avoid the
+  OpenBLAS at-fork SIGSEGV.
diff --git a/source/isaaclab_rl/setup.py b/source/isaaclab_rl/setup.py
@@ -19,7 +19,8 @@
 # Minimum dependencies required prior to installation
 INSTALL_REQUIRES = [
     # generic
-    "numpy",
+    # !=2.3.5 dodges the broken OpenBLAS bundle; see source/isaaclab/setup.py.
+    "numpy>=2,!=2.3.5",
     "torch>=2.10",
     "torchvision>=0.25.0",  # ensure compatibility with torch 2.10.0
     "protobuf>=4.25.8,!=5.26.0",

diff --git a/source/isaaclab_tasks/changelog.d/jichuanh-pin-numpy-not-2-3-5.rst b/source/isaaclab_tasks/changelog.d/jichuanh-pin-numpy-not-2-3-5.rst
@@ -0,0 +1,6 @@
+Fixed
+^^^^^
+
+* Excluded NumPy 2.3.5 from the install constraint (``numpy>=2,!=2.3.5``) to match
+  :file:`isaaclab/setup.py` and avoid the OpenBLAS at-fork SIGSEGV during Kit
+  startup.
diff --git a/source/isaaclab_tasks/setup.py b/source/isaaclab_tasks/setup.py
@@ -18,7 +18,8 @@
 # Minimum dependencies required prior to installation
 INSTALL_REQUIRES = [
     # generic
-    "numpy>=2",
+    # !=2.3.5 dodges the broken OpenBLAS bundle; see source/isaaclab/setup.py.
+    "numpy>=2,!=2.3.5",
     "torch>=2.10",
     "torchvision>=0.25.0",  # ensure compatibility with torch 2.10.0
     "protobuf>=4.25.8,!=5.26.0",

diff --git a/source/isaaclab_visualizers/changelog.d/jichuanh-pin-numpy-not-2-3-5.rst b/source/isaaclab_visualizers/changelog.d/jichuanh-pin-numpy-not-2-3-5.rst
@@ -0,0 +1,6 @@
+Fixed
+^^^^^
+
+* Tightened the NumPy install constraint to ``numpy>=2,!=2.3.5`` (was unconstrained)
+  to keep the package consistent with :file:`isaaclab/setup.py` and avoid the
+  OpenBLAS at-fork SIGSEGV.
diff --git a/source/isaaclab_visualizers/setup.py b/source/isaaclab_visualizers/setup.py
@@ -10,7 +10,8 @@
 # Base requirements shared across visualizer backends.
 INSTALL_REQUIRES = [
     "isaaclab",
-    "numpy",
+    # !=2.3.5 dodges the broken OpenBLAS bundle; see source/isaaclab/setup.py.
+    "numpy>=2,!=2.3.5",
 ]
 
 # Every Newton declaration in the repo must use the SAME extra spec (`newton[sim]`).