So my problem is that there seems to be little or no documentation about how this whole thing is supposed to work. So far cobbling things together has not been very productive for me, and while responses I’ve gotten in IRC and the issue tracker have been helpful, it’s been clear to me that this whole use case of controlling how Rust is (self-) compiled is really not a priority for the team. And I sort of understand that, but I also think providing some high-level documentation about how the system is supposed to work could be high leverage.
Or maybe Gentoo is just more critical in how we try to control the build system, and/or I’m too fussy/critical of how things are supposed to work.