Cross-compilers are always a nightmare to set up. Because compiling Rust code on a RPiZW is so slow, I wanted to set up Rust to cross-compile to it. As it turns out, Rust requires a C cross compiler toolchain in order to do that, so I installed crosstool-ng on macOS in order to build one. I wanted to have that toolchain somewhere in /usr/local, but unfortunately, a case-sensitive file system is required. Since I don't like the workaround of having a disk image mounted, the project stops there.
2) My beef with installing software that requires a lot of setup and doesn't have an uninstaller is that I won't remember what I've done, and all sorts of junk ends up clogging /usr/local. Even package managers are a little bit weak in that department, since you can't tag installed packages with your reason for installing them (say, to manually compile something), so unless you keep meticulous logs of everything, they'll just sit around forever.