Compilation errors when trying to build GCC

[Hrishi]

Thanks a lot for the help, I don't recall changing the gawk version, but I
did have some issues earlier while downloading the packages since my
network connection wasn't very stable- I'll try reading over the book and
check if I missed anything weird.

On Mon, 10 Aug 2026, 07:09 Xi Ruoyao <xry111@xry111.site> wrote:

>
> 在 2026/8/10 06:02, Hrishi via Gcc-help 写道:
> > Hello!
> > I've been attempting  a Linux From Scratch install as a summer project
> for
> > university applications and what not. I've run into a little bit of a
> > problem when compiling gcc however, whenever i try to compile gcc
> (version
> > 16.2.0) on the system after chrooting in; (a cross compilation is first
> > done so I do have access to a gcc compiler, not a complete one though)
> >
> > I have glibc version 2.43, binutils version 2.45 and a cross compiled gcc
> > and libstdc++ of version 16.2.0 .
> >
> > here are the configure flags:
> >
> > ../configure --prefix=/usr            \
> >               LD=ld                    \
> >               --enable-languages=c,c++ \
> >               --enable-default-pie     \
> >               --enable-default-ssp     \
> >               --enable-host-pie        \
> >               --enable-targets=all     \
> >               --disable-multilib       \
> >               --disable-bootstrap      \
> >               --disable-fixincludes    \
> >               --with-system-zlib
> >
> >
> > and below are the errors i encountered during my attempt at compilation:
> > ---
> > options.cc:27216:2: error: #error 0Wabsolute-value does not have a Var()
> > flag
> > 27216 | #error 0Wabsolute-value does not have a Var() flag
>
> Because gawk is buggy.  If gawk-5.4.1 is built without mpfr you'll hit
> the bug.
> That's why we (the LFS editors) moved ch.08 gawk earlier than GCC.
>
> > I've attempted to ask for help in the #lfs-support irc channel, but felt
> it
> > would probably be well to also request help from the GCC devs themselves.
>
> No, it contradicts with what we say in the book
> (
> https://www.linuxfromscratch.org/lfs/view/systemd/chapter01/askforhelp.html
> ):
>
>     In case you've hit an issue building one package with the LFS
>     instruction, we strongly
>     discourage posting the issue directly onto the upstream support
>     channel before
>     discussing via a LFS support channel listed in Section 1.4,
>     “Resources.” Doing so is
>     often quite inefficient because the upstream maintainers are rarely
>     familiar with LFS
>     building procedure. Even if you've really hit an upstream issue, the
>     LFS community
>     can still help to isolate the information wanted by the upstream
>     maintainers and
>     make a proper report.
>
> And this incident itself proves the points: this is actually a gawk
> issue instead of
> gcc issue; the gawk issue only manifests if it's not built with mpfr
> (and such a build
> does not occur frequently out of LFS so the GCC maintainers are
> generally not familiar
> with such a build); and the gawk issue was firstly identified by the LFS
> manage editor
> and he has already worked it around for the book.
>
> Apparently you are reading the instructions from an old LFS release but
> changing
> the gawk version on your own (because we don't have a revision where
> gawk is 5.4.1
> but it's not moved before GCC in chapter 8).  This is not good for a
> first-time builder
> and we already state that.  In the book
> (
> https://www.linuxfromscratch.org/lfs/view/systemd/partintro/generalinstructions.html
> ):
>
>     During a development cycle of LFS, the instructions in the book are
>     often modified
>     to adapt for a package update or take the advantage of new features
>     from updated
>     packages. Mixing up the instructions of different versions of the
>     LFS book can cause
>     subtle breakages.
>
> And in the FAQ (https://www.linuxfromscratch.org/faq/#why-not-version):
>
>     If this is your first time building LFS, using a version not in the
>     book or varying from the
>     book in any way is not a good idea. The IRC channel regulars have a
>     saying, "FBBG",
>     meaning "Follow Book, Book Good." They and the people on the lists
>     have helped many
>     an unhappy newbie who deviated from the book during that first build.
>
> Now you can see we state things in the book for a reason... Please do
> not skip them.
>
>