https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88535
--- Comment #14 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> --- > --- Comment #11 from john henning <mailboxnotfound at yahoo dot com> --- >> There are 3 different switches: --build, --host and --target. > > Hmm. I must be looking in the wrong place for documentation; are these > explained somewhere? > > At https://gcc.gnu.org/install/configure.html I see a description of > --target > and a brief mention of > --host > but no definition. There doesn't seem to be a description for --build. That's because all three are common configure switches, thus described in the autoconf manual. If none is given, config.guess tries it's best to determine them. Otherwise, the --host value defaults to the --build one if not given explicitly, and likewise --target to --host. I've seen cases (don't remember the details) when this didn't work as expected, so I tend to pass all three to avoid trouble (like configure configure wrongly assuming it's a cross build when in fact it's a native one).
