Fix ncurses build: disable pid-sandbox

This was failing to build due to a script that references its own PID
interacting with a failed Portage pid-sandbox setup.  The build
container doesn't have permissions to establish a new PID namespace and
it's not needed anyway because it's already containerized.  Just disable
the pid-sandbox.

.gitlab-ci.yml

@@ -16,6 +16,7 @@ default:
                    --security-opt seccomp=unconfined
                    --build-arg GENTOO_STAGE3_TAG=amd64
                    --build-arg EMERGE_DEFAULT_OPTS="--jobs=${JOBS} --usepkg"
+                   --build-arg FEATURES="-pid-sandbox"
                    --build-arg MAKEOPTS="-j${JOBS}"
                    --build-arg PROFILE="haswell/server"
                    -v /nest:/nest

Containerfile

@@ -4,6 +4,7 @@ FROM nest/gentoo/portage AS gentoo-portage
 FROM nest/gentoo/stage3:${GENTOO_STAGE3_TAG}
 
 ARG EMERGE_DEFAULT_OPTS
+ARG FEATURES
 ARG MAKEOPTS
 ARG PROFILE
 
@@ -16,12 +17,9 @@ COPY --from=nest-overlay / /var/db/repos/nest/
 
 # Rebuild all packages using a custom profile
 RUN eselect profile set "nest:${PROFILE}"
-RUN emerge --info && emerge -v1 sys-apps/portage && emerge --info
-RUN emerge -v1 sys-libs/libcap
-RUN MAKEOPTS='-j1' emerge -v1 sys-libs/ncurses
-RUN emerge -vDuN --with-bdeps=y @world
+RUN emerge --info && emerge -v1 sys-apps/portage
+RUN emerge --info && emerge -ev @world
 RUN emerge --depclean
-RUN emerge -ev @world
 
 # Install Puppet and prep package provider
 RUN emerge -v app-admin/puppet app-portage/eix