Here is my status report for March 2023.
At the end of February, I was trying to fix the issues about RLBox reproducibly. So, at the beginning of March, I started from there and managed to solve the problem.
As a result, we finally enabled RLBox in Tor Browser 12.5a4 .
I also sent a PR to the upstream project, and it is part of the latest WASI SDK release.
After that, I worked on the Tor Browser updater. I cleaned up a few macros and configuration options  first, and then I tried to split our updater patches to apply part of them also to the Base Browser part of the patchset .
They are part of the most delicate patches, so I needed to be extra careful. Therefore, I preferred reworking them while keeping the final diff as small as possible and postponing further improvements and refinements.
I also learned to set up a mock update server, which gave me more confidence that my patches were correct.
Then, I finally reviewed the msim's patches to make WebRTC buildable with MinGW . He did an outstanding job on it.
Also, this allowed us to find that Firefox IPC mechanisms have some problems when built with MinGW . I definitely enjoyed diving into the crash we had and analyzing its root causes.
Another task I had was checking the automatic outgoing connections in Base Browser and trying to block the remaining ones.
At the end of the month, I restarted refactoring the remaining code from torbutton.
While it has not been a standalone extension for many years, it kept living as an essential part of Tor Browser. However, we would like to modernize its code, drop all the XPCOM parts we can, and integrate it even more with the rest of our patches.
We started a few months ago by moving inside the same repository as the browser and deprecating torbutton.git. However, the most disruptive changes will have to wait at least for 13.0 because we are in an advanced stage of 12.5.
I expect to work on this in April since doing that before the next ESR update might make the transition easier. Then, we would like to start with the rebase on 115 when it reaches nighly, at the beginning of May.
 Re-enable rlbox (#40353) · Issues · The Tor Project / Applications / tor-browser-build · GitLab
 Use sorted inputs in the Makefile by PieroV · Pull Request #399 · WebAssembly/wasi-libc · GitHub
 Turn --enable-base-browser in --with-base-browser-version (#41647) · Issues · The Tor Project / Applications / Tor Browser · GitLab
 Remove --enable-tor-browser-data-outside-app-dir (#41657) · Issues · The Tor Project / Applications / Tor Browser · GitLab
 Move part of the updater patches to base browser (#41668) · Issues · The Tor Project / Applications / Tor Browser · GitLab
 Bug 41459: WebRTC fails to build under mingw (!460) · Merge requests · The Tor Project / Applications / Tor Browser · GitLab
 Failing tests at webrtc.github.io/test-pages (#41489) · Issues · The Tor Project / Applications / Tor Browser · GitLab
 Disable the network process on Windows (#41683) · Issues · The Tor Project / Applications / Tor Browser · GitLab
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