Revert "Build using per-job cache"

This reverts commit 6485c2dd.

.gitlab-ci.yml

@@ -6,16 +6,12 @@ variables:
   image: '${CI_REGISTRY}/nest/stage1:${CPU}-workstation'
   stage: 'build'
   tags: ['nest']
-  cache:
-    key: '$CI_JOB_NAME'
-    paths:
-      - 'portage/'
   script:
     - 'export EMERGE_DEFAULT_OPTS="$CI_HOST_EMERGE_DEFAULT_OPTS"
               MAKEOPTS="$CI_HOST_MAKEOPTS"
-              PORTAGE_TMPDIR=.'
+              PORTAGE_TMPDIR=/cache'
     - 'emerge --sync'
-    - '[ -d ./portage/.distcc ] || emerge -v1 -j1 -k n app-arch/snappy'
+    - '[ -d /cache/portage/.distcc ] || emerge -v1 -j1 -k n app-arch/snappy'
     - 'emerge -v --onlydeps --usepkg "=www-client/chromium-${VERSION}"'
     - 'ebuild "/var/db/repos/gentoo/www-client/chromium/chromium-${VERSION}.ebuild" package'
 
@@ -24,7 +20,7 @@ variables:
   variables:
     CPU: 'haswell'
 
-'Build cortex-a72-a53-crypto':
+.'Build cortex-a72-a53-crypto':
   <<: *template
   variables:
     CPU: 'cortex-a72-a53-crypto'