Re: [gentoo-dev] [PATCH] toolchain-funcs.eclass: tc-env_build: override (E)SYSROOT

[Mike Gilbert <floppym@gentoo.org>]

On Fri, Apr 19, 2024 at 1:56 PM James Le Cuirot <chewi@gentoo.org> wrote:
>
> On Fri, 2024-04-19 at 12:14 -0400, Mike Gilbert wrote:
> > When using the CBUILD toolchain, it makes no sense to look for headers
> > and libraries in the CHOST-based SYSROOT.
> >
> > Signed-off-by: Mike Gilbert <floppym@gentoo.org>
> > ---
> >  eclass/toolchain-funcs.eclass | 8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/eclass/toolchain-funcs.eclass b/eclass/toolchain-funcs.eclass
> > index cde84e6f34c8..58a718180079 100644
> > --- a/eclass/toolchain-funcs.eclass
> > +++ b/eclass/toolchain-funcs.eclass
> > @@ -1,4 +1,4 @@
> > -# Copyright 2002-2023 Gentoo Authors
> > +# Copyright 2002-2024 Gentoo Authors
> >  # Distributed under the terms of the GNU General Public License v2
> >
> >  # @ECLASS: toolchain-funcs.eclass
> > @@ -384,6 +384,12 @@ tc-export_build_env() {
> >  # the target build system does not check.
> >  tc-env_build() {
> >       tc-export_build_env
> > +     local -x SYSROOT=
> > +     if [[ ${EAPI} == 6 ]]; then
> > +             local -x ESYSROOT=${EPREFIX}
> > +     else
> > +             local -x ESYSROOT=${BROOT}
> > +     fi
> >       CFLAGS=${BUILD_CFLAGS} \
> >       CXXFLAGS=${BUILD_CXXFLAGS} \
> >       CPPFLAGS=${BUILD_CPPFLAGS} \
>
> What do you need this for? Just wondering because I wouldn't have thought
> anything you wrap with tc-env_build would care about ESYSROOT.

I ran into this when converting dev-build/ninja to use cmake.eclass.
Basically, I need to invoke ninja to build its own docs. I accomplish
this by building a second "native" (CBUILD) copy of ninja when
cross-compiling.

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=1122aa04647a60de150811c133490d248de4bc43

cmake.eclass utilizes ESYSROOT when SYSROOT is not empty.

https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/cmake.eclass?id=1122aa04647a60de150811c133490d248de4bc43#n503

If I don't set SYSROOT to empty when building the "native" ninja, it
explodes with a segfault when I invoke it in the ebuild.