Desync on Arch Linux + Ruffle

[Perdu]

I've mentioned this on Discord before, opening a proper issue.

On Arch Linux, I have desyncs which I don't have when running inside a Debian 12 docker environment.

LibTAS version is the same, ruffle version is the same, .swf file is the same, FPS is the same, .ltm file is the same. libopenh264 is already loaded in both cases.

Debian 12 (inside docker):

Arch Linux:

Since I took over the AUR packaging, I said I'd try to get this fixed.

I'm really unsure where to even start looking at to fix this

[Perdu]

Logs on Arch Linux. There's a difference in libopenh264 versions, but it's using the cached correct version anyway

Interim commit a6748b4f built on 2026-01-26
Setting CAP_CHECKPOINT_RESTORE capability to libTAS will allow some optimizations during savestates.
To do that, run the following command: `sudo setcap cap_checkpoint_restore+eip "$(which libTAS)"`
Attempt 1: Connected.
1970-01-01T00:00:01.000000Z  WARN winit::platform_impl::linux::x11::xdisplay: error setting XSETTINGS; Xft options won't reload automatically
1970-01-01T00:00:01.000000Z  WARN fontdb: Failed to load a font face 0 from '/usr/share/texmf-dist/fonts/opentype/public/helmholtz-ellis-ji-notation/HEJI2Text.otf' cause font doesn't have a family name.
1970-01-01T00:00:01.071000Z  INFO ruffle_desktop::gui::controller: Using preferred backend Open GL
1970-01-01T00:00:01.072000Z  INFO ruffle_desktop::gui::controller: Using graphics API gl on llvmpipe (LLVM 21.1.6, 256 bits) (type: Cpu)
1970-01-01T00:00:01.076000Z  WARN ruffle_desktop::gui::theme: Failed to instantiate FreedesktopSettings: A portal frontend implementing `org.freedesktop.portal.Settings` was not found
1970-01-01T00:00:01.077000Z  WARN egui_wgpu::renderer: Detected a linear (sRGBA aware) framebuffer Rgba8UnormSrgb. egui prefers Rgba8Unorm or Bgra8Unorm
1970-01-01T00:00:01.078000Z  INFO ruffle_desktop::gui::controller: Registering font NimbusSansNarrow-Regular as Proportional
1970-01-01T00:00:01.078000Z  WARN ruffle_desktop::gui::controller: Failed to register [Name("Noto Sans CJK"), Name("Source Han Sans"), Name("WenQuanYi Zen Hei"), Name("Arial Unicode MS")] as Proportional: no unicode fonts found!
1970-01-01T00:00:01.078000Z  INFO ruffle_desktop::gui::controller: Registering font NotoSansCJKkr-Regular as Proportional
1970-01-01T00:00:01.078000Z  INFO ruffle_desktop::gui::controller: Registering font NotoSansCJKjp-Regular as Proportional
1970-01-01T00:00:01.078000Z  INFO ruffle_desktop::gui::controller: Registering font NotoSansCJKsc-Regular as Proportional
1970-01-01T00:00:01.078000Z  INFO ruffle_desktop::gui::controller: Registering font NotoSansCJKtc-Regular as Proportional
1970-01-01T00:00:01.078000Z  INFO ruffle_desktop::gui::controller: Registering font NotoSansHebrew-Regular as Proportional
1970-01-01T00:00:01.078000Z  INFO ruffle_desktop::gui::controller: Registering font NotoSansArabic-Regular as Proportional
1970-01-01T00:00:01.078000Z  INFO ruffle_desktop::gui::controller: Registering font NotoSansThai-Regular as Proportional
1970-01-01T00:00:01.078000Z ERROR ruffle_desktop::player: Unable to create audio device: Failed to get default output config
1970-01-01T00:00:01.078000Z  WARN ruffle_video_external::decoder::openh264: Failed to load system OpenH264 library libopenh264.so.7: Error while loading OpenH264: libopenh264.so.7: cannot open shared object file: No such file or directory
1970-01-01T00:00:01.078000Z  WARN ruffle_video_external::decoder::openh264: Failed to load system OpenH264 library libopenh264.so.2.4.1: Error while loading OpenH264: libopenh264.so.2.4.1: cannot open shared object file: No such file or directory
1970-01-01T00:00:01.078000Z  WARN ruffle_video_external::decoder::openh264: Failed to load system OpenH264 library libopenh264.so: OpenH264 version mismatch, expected 2.4.1, was 2.6.0
1970-01-01T00:00:01.078000Z  INFO ruffle_video_external::decoder::openh264: Using OpenH264 at "/home/user/.cache/ruffle/video/libopenh264-2.4.1-linux64.7.so"
1970-01-01T00:00:01.093000Z  INFO ruffle_core::context: Loaded SWF version 6, resolution 792x600 @ 120 FPS
1970-01-01T00:00:01.094000Z  WARN ruffle_desktop::dbus: Failed to register a game with gamemode: ZBus Error: invalid value: -2, expected 0 or -1

Logs on Debian 12:

Interim commit a6748b4f built on 2026-01-26
Setting CAP_CHECKPOINT_RESTORE capability to libTAS will allow some optimizations during savestates.
To do that, run the following command: `sudo setcap cap_checkpoint_restore+eip "$(which libTAS)"`
Loaded script /home/lua/n_start.lua
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
libGL error: failed to open /dev/dri/card0: No such file or directory
libGL error: failed to load driver: nouveau
sh: 1: readelf: not found
Attempt 1: Connected.
sh: 1: readelf: not found
1970-01-01T00:00:01.000000Z  WARN winit::platform_impl::linux::x11::xdisplay: error setting XSETTINGS; Xft options won't reload automatically
error: XDG_RUNTIME_DIR is invalid or not set in the environment.
1970-01-01T00:00:01.000000Z  INFO ruffle_desktop::gui::controller: Using preferred backend Open GL
1970-01-01T00:00:01.000000Z  INFO ruffle_desktop::gui::controller: Using graphics API gl on llvmpipe (LLVM 15.0.6, 256 bits) (type: Cpu)
1970-01-01T00:00:01.000000Z  WARN ruffle_desktop::gui::theme: Failed to instantiate FreedesktopSettings: ZBus Error: I/O error: No such file or directory (os error 2)
1970-01-01T00:00:01.000000Z  WARN egui_wgpu::renderer: Detected a linear (sRGBA aware) framebuffer Rgba8UnormSrgb. egui prefers Rgba8Unorm or Bgra8Unorm
1970-01-01T00:00:01.000000Z  WARN ruffle_desktop::gui::controller: Failed to register [SansSerif] as Proportional: no unicode fonts found!
1970-01-01T00:00:01.000000Z  WARN ruffle_desktop::gui::controller: Failed to register [Name("Noto Sans CJK"), Name("Source Han Sans"), Name("WenQuanYi Zen Hei"), Name("Arial Unicode MS")] as Proportional: no unicode fonts found!
1970-01-01T00:00:01.000000Z  WARN ruffle_desktop::gui::controller: Failed to register [Name("Noto Sans CJK KR"), Name("Malgun Gothic")] as Proportional: no unicode fonts found!
1970-01-01T00:00:01.000000Z  WARN ruffle_desktop::gui::controller: Failed to register [Name("Noto Sans CJK JP"), Name("MS UI Gothic")] as Proportional: no unicode fonts found!
1970-01-01T00:00:01.000000Z  WARN ruffle_desktop::gui::controller: Failed to register [Name("Noto Sans CJK SC"), Name("Microsoft YaHei")] as Proportional: no unicode fonts found!
1970-01-01T00:00:01.000000Z  WARN ruffle_desktop::gui::controller: Failed to register [Name("Noto Sans CJK TC"), Name("Microsoft JhengHei")] as Proportional: no unicode fonts found!
1970-01-01T00:00:01.000000Z  WARN ruffle_desktop::gui::controller: Failed to register [Name("Noto Sans Hebrew"), Name("Tahoma")] as Proportional: no unicode fonts found!
1970-01-01T00:00:01.000000Z  WARN ruffle_desktop::gui::controller: Failed to register [Name("Noto Sans Arabic"), Name("Tahoma")] as Proportional: no unicode fonts found!
1970-01-01T00:00:01.000000Z  WARN ruffle_desktop::gui::controller: Failed to register [Name("Noto Sans Thai"), Name("Tahoma")] as Proportional: no unicode fonts found!
1970-01-01T00:00:01.000000Z ERROR ruffle_desktop::player: Unable to create audio device: Failed to get default output config
1970-01-01T00:00:01.000000Z  WARN ruffle_frontend_utils::write: missing or invalid 'recent' array, recreating..
1970-01-01T00:00:01.000000Z  WARN ruffle_video_external::decoder::openh264: Failed to load system OpenH264 library libopenh264.so.7: Error while loading OpenH264: libopenh264.so.7: cannot open shared object file: No such file or directory
1970-01-01T00:00:01.000000Z  WARN ruffle_video_external::decoder::openh264: Failed to load system OpenH264 library libopenh264.so.2.4.1: Error while loading OpenH264: libopenh264.so.2.4.1: cannot open shared object file: No such file or directory
1970-01-01T00:00:01.000000Z  WARN ruffle_video_external::decoder::openh264: Failed to load system OpenH264 library libopenh264.so: Error while loading OpenH264: libopenh264.so: cannot open shared object file: No such file or directory
1970-01-01T00:00:01.000000Z  INFO ruffle_video_external::decoder::openh264: Using OpenH264 at "/root/.cache/ruffle/video/libopenh264-2.4.1-linux64.7.so"
1970-01-01T00:00:01.000000Z  WARN ruffle_desktop::dbus: Failed to initialize gamemode controller: ZBus Error: I/O error: No such file or directory (os error 2)
1970-01-01T00:00:01.000000Z  INFO ruffle_core::context: Loaded SWF version 6, resolution 792x600 @ 120 FPS
1970-01-01T00:00:01.050000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans" (bold: false, italic: false) from file
1970-01-01T00:00:01.050000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans Bold" (bold: true, italic: false) from file
1970-01-01T00:00:01.050000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans Mono" (bold: false, italic: false) from file
1970-01-01T00:00:01.050000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Serif" (bold: false, italic: false) from file
1970-01-01T00:00:01.050000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans Mono Bold" (bold: true, italic: false) from file
1970-01-01T00:00:01.050000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Serif Bold" (bold: true, italic: false) from file
1970-01-01T00:00:01.050000Z  WARN ruffle_core::library: Unknown device font "Courier New" (bold: false, italic: false)
1970-01-01T00:00:01.050000Z  WARN ruffle_core::library: Unknown device font "Cousine" (bold: false, italic: false)
1970-01-01T00:00:01.050000Z  WARN ruffle_core::library: Unknown device font "Liberation Mono" (bold: false, italic: false)
1970-01-01T00:00:01.050000Z  WARN ruffle_core::avm1::fscommand: Unhandled FSCommand: allowscale
1970-01-01T00:00:01.050000Z  WARN ruffle_core::avm1::fscommand: Unhandled FSCommand: showmenu
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Serif" (bold: false, italic: false) from file
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Serif Bold" (bold: true, italic: false) from file
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans" (bold: false, italic: false) from file
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans Mono" (bold: false, italic: false) from file
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans Bold" (bold: true, italic: false) from file
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans Mono Bold" (bold: true, italic: false) from file
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans" (bold: false, italic: false) from file
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans Bold" (bold: true, italic: false) from file
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans Mono" (bold: false, italic: false) from file
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Serif" (bold: false, italic: false) from file
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Sans Mono Bold" (bold: true, italic: false) from file
1970-01-01T00:00:01.051000Z  INFO ruffle_core::library: Loaded new device font "DejaVu Serif Bold" (bold: true, italic: false) from file

[clementgallet]

The first thing to check is if those red frames are caused by sleeps or by time tracking.

For exemple, you can print "Sleep" and "Main Thread" in the debug logging options (together with level "Trace") to see if you are seeing calls. Depending on your ruffle version, you can uncheck the time-tracking option and the game will run fine.

[Perdu]

I got that:

[f:32 t:16134M] TRACE: epoll_wait call with timeout 0                                                                                                            
[f:34 t:16134M] TRACE: epoll_wait call with timeout 0                                                                                                            
[f:35 t:16134M] TRACE: epoll_wait call with timeout 0                                                                                                            
[f:36 t:16134M] TRACE: epoll_wait call with timeout 0                                                                                                            
1970-01-01T00:00:01.902000Z  WARN ruffle_core::avm1::fscommand: Unhandled FSCommand: allowscale                                                                  
1970-01-01T00:00:01.902000Z  WARN ruffle_core::avm1::fscommand: Unhandled FSCommand: showmenu                                                                    
[f:37 t:16134M] TRACE: epoll_wait call with timeout 0 
[...]

 + a lot of font-related info & warnings

Unchecking clock_gettime() monotonic did not fix the issue