Question

The --sysroot switch is useful when you don’t want the headers/libraries in the standard paths affect your build.

--sysroot=dir: Use dir as the logical root directory for headers and
libraries. For example, if the
compiler would normally search for
headers in /usr/include and libraries
in /usr/lib, it will instead search
dir/usr/include and dir/usr/lib. [ref]

Can the same thing be accomplished through the use of environment variables, the gcc specs file, or any other methods that do not require command line switches?

Answer 1

If you can use environment variables you can add –sysroot to CFLAGS.