Introduction #

We are pleased to announce the release of Siril 1.4.2!

This maintenance release continues to refine Siril 1.4 with a focus on stability fixes, significant improvements to Python scripting — in particular GPU library management — and enhanced catalogue handling. It also introduces an experimental new Windows build for users hitting file count limitations.

What’s new in Siril 1.4.2 #

Bug fixes #

• Fixed crash in RGB composition: Siril no longer crashes when attempting to align RGB channels while a luminance layer is loaded but not checked
• Fixed data entry typos in Messier.csv: several incorrect entries in the Messier catalogue have been corrected (!991)
• Fixed crash from GTK code in command functions: resolved a crash caused by GTK code being called from command functions (!992)

GPU library management — major improvements #

Version 1.4.2 brings substantial improvements to the way Siril handles GPU libraries required by Python scripts. The detection logic is now much more capable, correctly identifying the GPU hardware installed on the system — including complex configurations such as machines equipped with both an integrated GPU and a discrete GPU. Based on what it finds, Siril can now recommend the most appropriate Python backend to install for a wide range of hardware configurations and supported frameworks.

Alongside these detection improvements, a new GPU_Manager script has been introduced. Its role is to separate GPU framework management from the processing scripts that simply need to use them. This manager provides:

• a summary of detected hardware,
• one-click installation of the recommended version of each supported framework,
• the ability to override automatic detection and manually install alternative versions when autodetection falls short,
• tools to test the functionality of installed frameworks,
• a clean uninstall option for frameworks that aren’t working correctly.

Python scripting improvements #

• Improved sirilpy.gpuhelper: better GPU detection and capabilities reporting for use by the Helper classes (!988)
• Improved sirilpy.ensure_installed: now handles package downgrades; new sirilpy.uninstall_package function added
• Sequence frame support: several Python methods can now operate on sequence frames in addition to single images (siril-scripts#86)
• Added list support in sirilpy.set_seq_frame_incl: a list of sequence frame numbers can now be passed directly (!995)
• Improved Python venv creation robustness (!990)

Catalogue improvements #

• Local caching of index ranges from remote SPCC catalogue: reduces reliance on remote queries and improves response time; improvements to user-agent handling and HTTP checks (!977, !978, !980)

UI improvements #

• Reimplemented file chooser button in the RGB composition tool: the GtkFileChooserButton UI has been reproduced and drag-and-drop support has been reimplemented to restore expected behavior (!979)

Windows: experimental UCRT64 build #

Starting with Siril 1.4.2, we are providing an experimental Windows build compiled with the UCRT64 toolchain, in addition to the standard MINGW64 build.

The MINGW64 build remains the default and recommended option for all users. The UCRT64 build is provided as an experimental alternative and will remain so throughout the entire 1.4 development branch. Its primary motivation is to lift the file count limitation that affects Siril on Windows: the MINGW64 toolchain imposes a hard cap of around 2048 files in a sequence, which can be a significant obstacle for users working with long imaging sessions. The UCRT64 build raises this limit to 8192 files.

Because this build is experimental, it has received less testing than the standard Windows installer. We encourage technically inclined users to try it and report any issues, but we recommend that most users continue using the standard MINGW64 installer until this build matures.

Upgrading to 1.4.2 #

We recommend all users of Siril 1.4.x to upgrade to version 1.4.2. The upgrade is fully compatible with your existing Siril configuration and data.

This release is particularly beneficial if you:

• Experience crashes in RGB composition or when using the command line interface
• Use Python scripts that rely on GPU-accelerated processing
• Encounter issues with remote SPCC catalogue queries
• Are a Windows user frequently hitting the file count limit in sequences

Looking ahead #

Development of Siril 1.5 continues on the master branch. For those seeking stability with the latest fixes, the 1.4 branch remains the recommended option.

Acknowledgments #

We thank everyone who reported issues and contributed feedback following the 1.4.1 release. Special thanks to our developers and testers who worked to address these issues quickly.

Thank you all, and happy image processing with Siril 1.4.2!

Report bugs #

If you encounter problems with Siril 1.4.2, please report them via the Siril GitLab site . For bugs encountered with scripts, it’s here .

Your feedback is essential to help us maintain and improve Siril!