Flatpak for Citron Emulator

Citron is a cutting-edge Nintendo Homebrew emulator. For more information, please visit our website.

To install the Flatpak version of Citron Emulator, please run the following below:

# Make sure you have git and flatpak-builder installed.
git clone --recursive https://github.com/Skerse/org.citron_emu.Citron.git
cd org.citron_emu.Citron
flatpak-builder build org.citron_emu.Citron.json
flatpak build-export export build
flatpak build-bundle export Citron.flatpak org.citron_emu.Citron --runtime-repo=https://flathub.org/repo/flathub.flatpakrepo
flatpak install Citron.flatpak

For issues with basic functionality and usage, please join our Discord channel.

Reporting Bugs

If you encounter any crashes or stability issues, please report them in the issues section of this repository.

When reporting, make sure to select the appropriate template and follow the instructions in the template.

Obtaining Necessary Information for Bug Reports

Since Citron is a complex piece of software, it's very difficult to pinpoint a specific issue. Providing necessary contextual information will help us determine the root cause of the problem you are experiencing.

Usually, Citron's own log file will reveal the issue. Please see How to obtain the log file for information on how to collect the log file from your system.

Sometimes, Citron's own log file is insufficient to determine the cause, especially if you are reporting a crash or a freeze. Ideally, we will able to reproduce the issue on our own machines. But there are times when we can't reproduce the crash or freeze on our own machines due to hardware differences. This would require you to provide a debugger trace. Obtaining a debugger trace is a bit complicated, so please bear with us:

Obtaining a debugger trace after the crash

1. Install debuggers in Flatpak: flatpak install org.kde.Sdk//6.8
2. Install debug information for Citron: flatpak install org.citron_emu.Citron.Debug
3. Execute this command in your terminal: flatpak-coredumpctl org.citron_emu.Citron -m citron --gdb-arguments "--batch -ex 'thread apply all bt'" > /tmp/citron-backtrace.log
4. Please attach the file /tmp/citron-backtrace.log file to your report

Obtaining a debugger trace as the crash happens

1. Install debuggers in Flatpak: flatpak install org.kde.Sdk//6.8
2. Install debug information for Citron: flatpak install org.citron_emu.Citron.Debug
3. Execute this command in your terminal: flatpak run --devel --command=sh org.citron_emu.Citron
4. Type gdb /app/bin/citron in the coming up prompt and wait for the (gdb) prompt to show up
5. Type r and hit Enter to launch Citron under the debugger
6. Before loading your game:
   • Go to Emulation -> Configure ... menu
   • Choose General on the left-sidebar, then choose Debug tab on the right panel. And then, select the CPU tab on the second-level panel, you will see the Toggle CPU optimizations options. Please uncheck both the Enable Host MMU Emulation (general memory instructions) and Enable Host MMU Emulation (exclusive memory instructions) checkboxes (as those would interfere with the debugger)
   • Then go to the Debug tab and check the Enable CPU Debugging checkbox
7. Load the game that caused the crash and repeat the steps you think that may have crashed or freezed Citron
8. When the crash or freeze happens, switch back to the terminal and type bt at the (gdb) prompt
9. If gdb asks --Type <RET> for more, q to quit, c to continue without paging--, type c to show all the output
10. Copy and paste all the output to a new text file, and attach this file to your report
11. Type q to kill both the debugger and crashed Citron
12. (Optional) You might want to undo step (6) to avoid performance penalty after this process