I think there has been some misinformation.
You can still build using GitHub - gl-inet/imagebuilder: Warning！Please look at 'GL.iNET Imagebuilder Introduction' section.
GL.iNet packages like the UI were never fully open source in the first place unless I’ve missed it, I never saw the claim, anyone have references?
GitHub - gl-inet/wlan-ap (for qualcomm) and other repos are still up for non-Mediatek kernel building…
^ Which are also not fully open source due to binary blobs & licensing with Qualcomm etc.
The gl-infra-builder facilitates building the packages while compiling the kernel, that tool has gone private, which doesn’t translate to going closed sourced.
We still have an imagebuilder to build GL.iNet images and modify it. The kernel is pre-compiled as well as the packages.
You can still compile your own packages with the official OpenWrt builder (for most packages) and modify the repository in the image builder.
You can still compile your own kernel separately.
Remember that some models use Qualcomm SoCs, these are not officially supported by OpenWrt and the ports are somewhat reverse-engineered, yet we can still build a fully functional custom firmware for a Qualcomm router which is not possible with any other vendor (yet) as far as I know.
No restrictions on flashing custom firmware is part of open source ethos.
My guess is that limiting to an image-builder only setup may be used to restrict others from running GL.iNet software and firmware on other hardware by having a dependency on the kernel. You’ll still be able to build the kernel by using the external repos, while the infra-builder now contains the already closed source Gl.inet packages + new kernel coupling for hardware lock. This makes the builds non-reproducible, and having the repo up without the lock code will have non-reproducible builds.
As far as I’m aware (unless I’m mistaken), the only thing we lost is one-click kernel + package compilation before building the image, which can still be done individually including hardware specific tuning like BDF is still there.
I’m having no issues building my custom firmware project so far after the repo has gone private by simply moving to imagebuilder.
*What's the difference between open source software and free software? | Opensource.com
Edit: To clarify, there is no point of having reproducible builds with binary blobs from other areas like Qualcomm, GL.iNet packages, so nothing have changed so far.