cross.rst

autotools var	CBUILD	CHOST
arch	native	target
dep type	BDEPEND	DEPEND	RDEPEND
unprefixed path	/	SYSROOT	ROOT
relevant prefix	BROOT	EPREFIX
prefixed path	BROOT	ESYSROOT	EROOT
autoconf var	---	--with-sysroot	n/a
has_version	--build-root or --bdepend	--host-root or --depend	(none) (--rdepend?)

Of course an entirely different problem is whether we assume that all three locations are guaranteed to use the same EPREFIX. If they aren't, then we should either:

1. have only variants with prefix embedded,
2. have full set of separate prefix variables for every one of them.

In this case, I think 1. is simply better as it kinda reduces the risk of confusion (i.e. mixing wrong prefixes).

Small update: I've talked to @ulm about this, and it seems that EPREFIX must be the same for / and ROOT because we pass EPREFIX to configure, and so configure implicitly expects to find paths in /${EPREFIX}... Not sure how --sysroot affects its behavior though but I suppose reusing EPREFIX there is also a safe assumption.

The question is whether configure appends --prefix to --sysroot.