Rebuild with 'build' fact instead of 'tool'

.gitlab-ci.yml

 ---
-default:
+.template: &template
   image: '${CI_REGISTRY}/nest/tools/buildah:${CI_HOST_CPU}'
-  before_script:
-    - 'buildah login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" "$CI_REGISTRY"'
-
-'Build haswell':
   stage: 'build'
   tags: ['nest']
   script:
     - 'mkdir debug'
-    - 'buildah bud --pull
-                   --security-opt seccomp=unconfined
-                   --build-arg STAGE1_TAG=haswell-server
+    - 'buildah login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" "$CI_REGISTRY"'
+    - 'buildah bud --security-opt seccomp=unconfined
+                   --build-arg STAGE1_TAG="${CPU}-server"
                    --build-arg FACTER_emerge_default_opts="$CI_HOST_EMERGE_DEFAULT_OPTS"
                    --build-arg FACTER_makeopts="$CI_HOST_MAKEOPTS"
                    -v "${PUPPET_CERTIFICATE}:/etc/puppetlabs/puppet/ssl/certs/ci.pem"
                    -v "${PUPPET_PRIVATE_KEY}:/etc/puppetlabs/puppet/ssl/private_keys/ci.pem"
                    -v "${PWD}/debug:/usr/lib/debug"
                    -v /nest:/nest
-                   -t "${CI_REGISTRY_IMAGE}:haswell" .'
-    - 'buildah bud --build-arg STAGE1_TAG=haswell-server -t "${CI_REGISTRY_IMAGE}/debug:haswell" -f Containerfile.debug .'
-    - 'buildah push "${CI_REGISTRY_IMAGE}:haswell"'
-    - 'buildah push "${CI_REGISTRY_IMAGE}/debug:haswell"'
+                   -t "${CI_REGISTRY_IMAGE}:${CPU}" .'
+    - 'buildah bud --build-arg STAGE1_TAG="${CPU}-server" -t "${CI_REGISTRY_IMAGE}/debug:${CPU}" -f Containerfile.debug .'
+    - 'buildah push "${CI_REGISTRY_IMAGE}:${CPU}"'
+    - 'buildah push "${CI_REGISTRY_IMAGE}/debug:${CPU}"'
+
+'Build haswell':
+  <<: *template
+  variables:
+    CPU: 'haswell'

Containerfile

 ARG STAGE1_TAG
 FROM nest/stage1:${STAGE1_TAG}
 
+ARG FACTER_build=r10k
 ARG FACTER_emerge_default_opts
 ARG FACTER_makeopts
 
 RUN eix-sync -q
-RUN FACTER_tool=r10k puppet agent --test --runtimeout 0; [ $? -eq 2 ]
+RUN puppet agent --test --runtimeout 0; [ $? -eq 2 ]
 RUN rm -rf /var/db/repos