gcc8 and "fatal error: had to relocate PCH" with boost-libs

[David Brownlee <abs%absd.org@localhost>]

I've been testing out building my working subset of pkgsrc with gcc8
on NetBSD/amd64 and most things work.

One issue I've hit is both boost-libs and opencv fail to build with
"fatal error: had to relocate PCH".
The only reference I've found for this was
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58379 which discusses
using the same TRY_EMPTY_VM_SPACE as mips and vax for arm to fix
wxGTK28 or wxGTK30 building on arm on an earlier gcc version.

Does anyone have any thoughts on what might be happening here?

For reference my nasty mk.conf hack to get this far is below.

Thanks

David

  BASE_COMPILER_PKGPATHS_GCC8=\
    \
    lang/gcc8 \
    pkgtools/digest \
    pkgtools/cwrappers \
    sysutils/checkperms \
    \
    devel/gmake \
    lang/perl5 \
    textproc/gsed \
    lang/python37 \
    devel/m4 \
    devel/libtool-base \
    devel/readline \
    devel/libffi \
    devel/pkgconf \
    devel/libuuid \
    archivers/bsdtar \

  BASE_COMPILER_PKGPATHS=${BASE_COMPILER_PKGPATHS_GCC8}

. if empty(BASE_COMPILER_PKGPATHS:M${PKGPATH})
    GCC_REQD+=8
. endif