Day: GNOME OS

The build farm is also running tests which I can imagine taking a long time. In fact, looking at the logs, they're using ccache which tells me that its 60 to 120 minutes of running tests which is more than the kernel can say.

Basically, your comparison is: "more" C is compiled by a top-of-the-line CPU in one minute than some random build farm hardware can test "less" C++ code. Never mind that the build farm builds also start by doing lots of PyPI installs (mostly cached) whereas the kernel build goes straight to building stuff.