Hi, it looks like having the C_INCLUDE_PATH and CPLUS_INCLUDE_PATH
environment variables set by the gcc-toolchain package in a profile can
cause issues.
For example, I have gcc-toolchain installed, compiled a cross-binutils
for aarch64-elf and then tried to compile a gcc cross-compiler for the
same target using those binutils.
These are the flags I used for binutils:
--target=aarch64-none-elf --disable-multilib
and for the gcc cross-compiler:
--target=aarch64-none-elf --disable-multilib --disable-bootstrap
--enable-languages=c,c++ --without-headers --with-newlib
--disable-hosted-libstdcxx --disable-libssp --disable-libsanitizer
From what I understand, there should be no headers available when
creating a cross-compiler for a freestanding platform like this.
Since these include paths were added with C_INCLUDE_PATH and
CPLUS_INCLUDE_PATH, something like `#if __has_include(<sys/auxv.h>)` in
gcc's libgcc/config/aarch64/cpuinfo.c evaluated to true and the rest of
the build would fail.
Unsetting them didn't work since apparently gcc-toolchain relies on them
set so I had these two variables unset in BASE_TARGET_EXPORTS in gcc's
root Makefile.in which should only apply to the newly built gcc
cross-compiler and so the build finished fine.
