Ubuntu 26.04 support for 6.0.0

[ScheglyakStas]

I've tried building IsaacSim 6.0.0 GA from source on Ubuntu 26.04 and got multiple errors like this one:

/usr/include/x86_64-linux-gnu/bits/mathcalls.h(83): error: exception specification is incompatible with that of previous function "cospi" (declared at line 2601 of /home/stas/isaacsim/_build/target-deps/cuda/include/crt/math_functions.h)
   extern double cospi (double __x) noexcept (true); extern double __cospi (double __x) noexcept (true);
                                    ^

Is Ubuntu 26.04 support planned for IsaacSim 6.0.0 in near future?

[vick-yu]

This is a known CUDA + glibc 2.41 incompatibility, not an Isaac Sim bug -- you're hitting an upstream issue that affects all CUDA builds on newer distros.

What's happening

Ubuntu 26.04 ships glibc 2.41, which added C23 math functions (cospi, sinpi, etc.) with noexcept(true) exception specifications. CUDA's headers declare the same functions without noexcept, and cudafe++ rejects the mismatch. This affects Ubuntu 25.04+, Fedora 43+, and Debian 13 -- not just Isaac Sim.

Upstream thread with the same issue: exception specification is incompatible for cospi/sinpi with glibc-2.41

Workaround

Patch your local CUDA headers to add noexcept(true). In _build/target-deps/cuda/include/crt/math_functions.h, around lines 2550-2617:

-extern __DEVICE_FUNCTIONS_DECL__ __device_builtin__ double sinpi(double x);
+extern __DEVICE_FUNCTIONS_DECL__ __device_builtin__ double sinpi(double x) noexcept(true);

-extern __DEVICE_FUNCTIONS_DECL__ __device_builtin__ float sinpif(float x);
+extern __DEVICE_FUNCTIONS_DECL__ __device_builtin__ float sinpif(float x) noexcept(true);

-extern __DEVICE_FUNCTIONS_DECL__ __device_builtin__ double cospi(double x);
+extern __DEVICE_FUNCTIONS_DECL__ __device_builtin__ double cospi(double x) noexcept(true);

-extern __DEVICE_FUNCTIONS_DECL__ __device_builtin__ float cospif(float x);
+extern __DEVICE_FUNCTIONS_DECL__ __device_builtin__ float cospif(float x) noexcept(true);

This works with CUDA 12.6-12.8+.

About Ubuntu 26.04 support

Ubuntu 26.04 isn't officially supported for Isaac Sim 6.0.0 (supported: Ubuntu 22.04 and 24.04). NVIDIA needs to update CUDA headers to fix this properly -- until then, the workaround above should unblock you.

If you're not tied to 26.04, Ubuntu 24.04 avoids this entirely.

[johnnynunez]

yes, I reported this internally! Thank you

[johnnynunez]

libxml2-dev is required and other fixes. I am reporting this internally! If you have any issues, please ping me