So I found out why #Tenacity #Windows runners were failing on 32-bit and 64-bit Windows: because compiler caching was actually still being used! I was not aware that those runner images came with #ccache already installed. Therefore we'll have to disable it manually.
NOW these runners should build. They may still fail their job due to other unknown issues, but we're getting closer to nightly Windows installers again, plus a new Windows in ARM installer! 😄