diskimage-builder/diskimage_builder/elements/gentoo/pre-install.d/02-gentoo-04-install-desired-python

#!/bin/bash

if [[ ${DIB_DEBUG_TRACE:-0} -gt 0 ]]; then
    set -x
fi
set -eu
set -o pipefail

if mountpoint -q /dev/shm; then
    echo "/dev/shm found in /proc/self/mountinfo"
elif [[ -k /dev/shm ]]; then
    echo "/dev/shm exists and is stickied"
else
    fix_shm
fi

[[ ! -f ${PORTDIR}/profiles ]] && emerge-webrsync -q

echo "PYTHON_TARGETS=\"${GENTOO_PYTHON_TARGETS}\"" >> /etc/portage/make.conf
[[ "${GENTOO_PYTHON_TARGETS}" == *"python3_6"* ]] && [[ ! -e /usr/lib64/libpython3.6m.so ]] && emerge ${GENTOO_EMERGE_DEFAULT_OPTS} --oneshot dev-lang/python:3.6
[[ "${GENTOO_PYTHON_TARGETS}" == *"python3_5"* ]] && [[ ! -e /usr/lib64/libpython3.5m.so ]] && emerge ${GENTOO_EMERGE_DEFAULT_OPTS} --oneshot dev-lang/python:3.5
[[ "${GENTOO_PYTHON_TARGETS}" == *"python3_4"* ]] && [[ ! -e /usr/lib64/libpython3.4m.so ]] && emerge ${GENTOO_EMERGE_DEFAULT_OPTS} --oneshot dev-lang/python:3.4
[[ "${GENTOO_PYTHON_TARGETS}" == *"python2_7"* ]] && [[ ! -e /usr/lib64/libpython2.7.so ]] && emerge ${GENTOO_EMERGE_DEFAULT_OPTS} --oneshot dev-lang/python:2.7
# disable python in git if we have to, it only supports python-2.7
[[ "${GENTOO_PYTHON_TARGETS}" != *"python2_7"* ]] && echo 'dev-vcs/git -python' >> /etc/portage/package.use/git

# make sure we have the new python for portage bevore we possibly remove python 2.7
# this is done one by one with nodeps because it can sometimes have dependency loops
PYTHON_PACKAGES="dev-python/six dev-python/packaging dev-python/appdirs dev-python/setuptools dev-python/pyparsing dev-python/certifi"
for PACKAGE in ${PYTHON_PACKAGES}; do
    emerge ${GENTOO_EMERGE_DEFAULT_OPTS} --oneshot --update --newuse --deep --nodeps "${PACKAGE}"
done
emerge ${GENTOO_EMERGE_DEFAULT_OPTS} --oneshot --update --newuse --deep --complete-graph=y sys-apps/portage dev-python/pyxattr
# set the active python version
eselect python set ${GENTOO_PYTHON_ACTIVE_VERSION}
# allow these uninstalls to fail as they may not be installed to begin with
set +e
[[ "${GENTOO_PYTHON_TARGETS}" != *"python2_7"* ]] && emerge -C -q dev-lang/python:2.7
[[ "${GENTOO_PYTHON_TARGETS}" != *"python3_4"* ]] && emerge -C -q dev-lang/python:3.4
[[ "${GENTOO_PYTHON_TARGETS}" != *"python3_5"* ]] && emerge -C -q dev-lang/python:3.5
[[ "${GENTOO_PYTHON_TARGETS}" != *"python3_6"* ]] && emerge -C -q dev-lang/python:3.6
set -e

# make world consistant
emerge ${GENTOO_EMERGE_DEFAULT_OPTS} --complete-graph=y --update --newuse --deep @world
# rebuild packages that might need it
emerge ${GENTOO_EMERGE_DEFAULT_OPTS} --usepkg=n @preserved-rebuild
# remove unneeded packages
emerge --verbose=n --depclean
# rebuild packages that might have somehow depended on the unneeded packages
emerge ${GENTOO_EMERGE_DEFAULT_OPTS} --usepkg=n @preserved-rebuild

unfix_shm