Game crashes with segmentation fault when focus lost. Only happens when both Dynamic FPS and Sodium are enabled. If either mod is disabled, the issue is not present. The problem occurs consistently.

System:

• Fedora Linux 42 (Wayland, kernel 6.16.7, mesa 25.1.7)
• Hardware: AMD Ryzen 7 9800X3D (8-core), AMD Radeon RX 6950 XT (16 GB), DDR5-6200 CL30 (64 GB)
• Minecraft 1.21.1, Fabric 0.17.2

Enabled mods:

• Dynamic FPS
• Sodium
• Fabric API (required)

Tested with versions:

Dynamic FPS

3.9.5, 3.9.4, 3.8.0

Sodium

0.6.13, 0.6.9, 0.6.5

Tested as well with Adoptium Temurin 21.

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007f95d60e7dbe, pid=2032, tid=2115
#
# JRE version: OpenJDK Runtime Environment Microsoft-11369942 (21.0.7+6) (build 21.0.7+6-LTS)
# Java VM: OpenJDK 64-Bit Server VM Microsoft-11369942 (21.0.7+6-LTS, mixed mode, tiered, compressed class ptrs, g1 gc, linux-amd64)
# Problematic frame:
# C  [libgallium-25.2.2.so+0xce7dbe]
#
# Core dump will be written. Default location: Core dumps may be processed with "/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %d %F" (or dumping to /home/zefir/.var/app/org.prismlauncher.PrismLauncher/data/PrismLauncher/instances/1.21.1/minecraft/core.2032)
#
# An error report file with more information is saved as:
# /home/zefir/.var/app/org.prismlauncher.PrismLauncher/data/PrismLauncher/instances/1.21.1/minecraft/hs_err_pid2032.log
#
# If you would like to submit a bug report, please visit:
#   https://aka.ms/minecraftjavacrashes
#

No relevant errors/warnings before the crash. Crash happens immediately on lost focus.

I can also reproduce this on Minecraft 1.21.1 to 1.21.4.

Some testing reveals that this issue only occurs when the new Dynamic FPS state has a frame rate target below 15, which is when the mod instructs Minecraft to skip rendering some frames by conditionally setting the Minecraft.noRender field to true instead of just lowering the FPS limit even further (see explanation).

If you'd like to use the two mods together with Zink on these Minecraft versions you can change the Dynamic FPS config so it will never go below this threshold, and everything should work fine.

That being said, I will close this issue since it is no longer present in the current Minecraft version (even though we still use the same mechanism to render <15 frames) and I also do not know how I would go about finding the cause at this time.

Thanks for the info. As I didn’t have this issue less than a month ago, I suspect it might be a regression in Mesa. For others hitting this, if you rely on Zink and can’t disable it, you could try downgrading Mesa. Release notes for newer versions mention various segfault, regression, and Zink fixes, though I’m not sure how relevant they are.

Can’t reproduce on a fresh instance with same versions. Open to suggestions

The issue is conditional on enabling Zink in Prism performance settings. With Zink enabled, I was able to reproduce the issue on another Fedora 42 machine (same mesa, older kernel) with an Intel CPU and Iris Xe iGPU (with Zink enabled).

If you think there is no issue in Dynamic FPS, please feel free to close.

For info: SIGSEGV w/ VANILLA Minecraft 1.21.8, Fedora 43 fully up to date, MESA 25.2.2-5.fc43. Regressing as follows fixes the issue:

Transaction ID : 39
Begin time : 2025-09-14 14:48:09
Begin rpmdb : 6d8056646cf7fdd3e63bbfb6005fccb82634721e080b2b013d317384a36310cf
End time : 2025-09-14 14:48:10
End rpmdb : 0a9a2d4a811d88f709f26562d4aae10a50917ebc89d1a8512097a42a2759fd4f
User :
Status : Ok
Releasever : 43
Description : dnf downgrade mesa-vulkan-drivers --allow-downgrade
Comment :
Packages altered:
Action Package Reason Repository
Downgrade mesa-vulkan-drivers-0:25.1.4-2.fc43.x86_64 Group fedora
Downgrade mesa-filesystem-0:25.1.4-2.fc43.x86_64 Dependency fedora
Downgrade mesa-va-drivers-0:25.1.4-2.fc43.x86_64 Weak Dependency fedora
Downgrade mesa-dri-drivers-0:25.1.4-2.fc43.x86_64 Dependency fedora
Downgrade mesa-libGL-0:25.1.4-2.fc43.x86_64 Dependency fedora
Downgrade mesa-libEGL-0:25.1.4-2.fc43.x86_64 Dependency fedora
Downgrade mesa-libgbm-0:25.1.4-2.fc43.x86_64 Dependency fedora
Replaced mesa-dri-drivers-0:25.2.2-5.fc43.x86_64 Dependency @System
Replaced mesa-filesystem-0:25.2.2-5.fc43.x86_64 Dependency @System
Replaced mesa-libEGL-0:25.2.2-5.fc43.x86_64 Dependency @System
Replaced mesa-libGL-0:25.2.2-5.fc43.x86_64 Dependency @System
Replaced mesa-libgbm-0:25.2.2-5.fc43.x86_64 Dependency @System
Replaced mesa-va-drivers-0:25.2.2-5.fc43.x86_64 Weak Dependency @System
Replaced mesa-vulkan-drivers-0:25.2.2-5.fc43.x86_64 Group @System

Failed to mention this is straight on initial install of Minecraft via the launcher.