Hi everyone, Here is my status report for June 2025. During the first week of the month, I attended the web engines hack fest [wehf]. After I came back, I've worked only on the ESR transition. First, I've finalized the toolchain updates [tor-browser-build!1212] [tor-browser-build!1232]. It took me a while to complete the MR for Android because we might have a reproducibility problem caused by the R8 optimizer [tor-browser-build#41495]. Eventually, I decided to send the MR for review, and to come back to reproducibility problems we might find when building 15.0a1. Also, I investigated our new APK sizing problems and modified our scripts to build little-t-tor and its dependencies with clang's option `-Oz` [tor-browser-build!1242]. In this way, we saved almost 400kB, which is not bad at all, considering our limit is 100MB. Then, when 140.0esr was released upstream, I rebased onto it. However, I still haven't opened an MR because we are switching to Firefox's new git history for it, and we needed to assess the effects on our infrastructure first. Finally, I commented the HTML version of the range-diff between 128 and 140-based Tor Browser, for making the review easier [tor-browser#43852]. Best, Pier [tor-browser#43852] https://gitlab.torproject.org/tpo/applications/tor-browser/-/work_items/4385... [tor-browser-build#41495] https://gitlab.torproject.org/tpo/applications/tor-browser-build/-/issues/41... [tor-browser-build!1212] https://gitlab.torproject.org/tpo/applications/tor-browser-build/-/merge_req... [tor-browser-build!1232] https://gitlab.torproject.org/tpo/applications/tor-browser-build/-/merge_req... [tor-browser-build!1242] https://gitlab.torproject.org/tpo/applications/tor-browser-build/-/merge_req... [wehf] https://webengineshackfest.org/