Cross-compiling fails with C++ code

Created by: PureTryOut

pmbootstrap.py tries to cross-compile packages, and although C code works fine, C++ doesn't. It falls back to GCC in qemu, and since Plasma Mobile is basically all C++ code, this makes compiling really slow.

pmbootstrap.py log_distccd reports (for example):

distccd[10023] (dcc_job_summary) client: 127.0.0.1:34472 COMPILE_ERROR exit:1 sig:0 core:0 ret:0 time:420ms g++ /home/user/build/src/solid-5.31.0/src/solid/devices/frontend/camera.cpp

An example APKBUILD (does not matter what package in practice, as long as it contains C++ code):

pkgname=karchive
pkgver=5.31.0
pkgrel=1
pkgdesc='Qt 5 addon providing access to numerous types of archives'
arch="all"
url='https://community.kde.org/Frameworks'
license="LGPL"
depends="qt5-qtbase"
makedepends="extra-cmake-modules doxygen qt5-qttools-dev"
source="https://download.kde.org/stable/frameworks/${pkgver%.*}/${pkgname}-${pkgver}.tar.xz"
validpgpkeys="53E6B47B45CEA3E0D5B7457758D0EE648A48B3BB" # David Faure <faure@kde.org>

prepare() {
  mkdir -p "$srcdir/build"
}

build() {
  cd "$srcdir/build"
  cmake ../${pkgname}-${pkgver} \
    -DCMAKE_BUILD_TYPE=Release \
    -DCMAKE_INSTALL_PREFIX=/usr \
    -DKDE_INSTALL_LIBDIR=lib \
    -DBUILD_TESTING=OFF
  make
}

package() {
  cd "$srcdir/build"
  make DESTDIR="${pkgdir}" install
}
sha512sums="4a82b91956bd52a7b9da6c40bcaa0340b3e1b0e964ce44be8993a6a62abde7514d449df1748a79a4bf7c8a7aacaaf4bc3f2b125a7748dde5f02a9ad5c49efb48  karchive-5.31.0.tar.xz"