[ Disclaimer: simplified, high-level view ahead. ] When a program reads or writes data at a given virtual address, it uses instructions telling the CPU to do so. When the CPU doesn’t know the address, it faults. When it knows the address, but its access rights don’t allow the read or write operation the program [...]

One of the longstanding problems when modifying code in the mozilla code base, is that when you change some file under e.g. content/, and you don’t want to waste the whole lot of time it takes to run a complete make -f client.mk, you need to build under content/, then layout/build/, and finally toolkit/library/. And [...]