Blender CUDA on Fedora: Why It Breaks and How to Fix It

19 January, 2026 - Categories: 3D

Blender CUDA on Fedora: Why It Breaks and How to Fix It

Blender’s Cycles renderer uses CUDA for GPU rendering on NVIDIA cards. If Blender can’t find a matching precompiled kernel, it compiles one locally using nvcc.

On Fedora 42, this can fail even when CUDA is installed correctly.

What goes wrong

The failure is caused by a mismatch between:

• Fedora’s glibc headers
• NVIDIA CUDA’s header declarations

In newer glibc versions, math functions like:

sinpi, cospi, sinpif, cospif

are declared with noexcept(true) (Don't ask - I don't know lol).

CUDA’s math_functions.h declares the same functions without noexcept. C++ treats this as a hard error, so nvcc fails during compilation and Blender reports a generic “failed to execute compilation command”.

This is not a Blender bug and not a user configuration error. CUDA simply hasn’t caught up with current glibc.

The fix

Patch CUDA’s math_functions.h so the function declarations match glibc.

This only changes exception specifications. Runtime behavior is unchanged.

Patch script

Save the following as, for example, fix-cuda-glibc.sh:

#!/usr/bin/env bash
set -e

CUDA_MATH=/usr/local/cuda/targets/x86_64-linux/include/crt/math_functions.h

# Backup
sudo cp -a "$CUDA_MATH" "${CUDA_MATH}.bak.$(date +%Y%m%d_%H%M%S)"

# Patch declarations to match glibc
sudo perl -pi -e 's/\bsinpi\(double x\);/sinpi(double x) noexcept(true);/g' "$CUDA_MATH"
sudo perl -pi -e 's/\bsinpif\(float x\);/sinpif(float x) noexcept(true);/g' "$CUDA_MATH"
sudo perl -pi -e 's/\bcospi\(double x\);/cospi(double x) noexcept(true);/g' "$CUDA_MATH"
sudo perl -pi -e 's/\bcospif\(float x\);/cospif(float x) noexcept(true);/g' "$CUDA_MATH"

echo "CUDA math_functions.h patched for glibc compatibility."

Then run:

chmod +x fix-cuda-glibc.sh
./fix-cuda-glibc.sh

After patching, clear Blender’s kernel cache and start Blender again:

rm -rf ~/.cache/cycles/kernels
blender

Notes

• The patch survives reboots.
• It may be overwritten by a CUDA update.
• If CUDA is updated and the problem returns, re-run the script.

tl;dr

This issue exists because Fedora updates glibc faster than CUDA updates its headers. When Blender compiles CUDA kernels locally, the mismatch becomes visible.

Until NVIDIA updates CUDA to match newer glibc versions, this small header patch is the practical fix.