i386 Debian builds need x86 builders

* .gitlab-ci.yml: split the amd64/i386 debian builds so we can tag the
latter with x86.

.gitlab-ci.yml

 stages:
   - build
+  - build2
   - publish
 
 debian-stable-gcc:
@@ -178,12 +179,10 @@ debpkg-stable:
     - stable
   script:
     - docker pull gitlab-registry.lrde.epita.fr/spot/buildenv/debian:stable
-    - docker pull gitlab-registry.lrde.epita.fr/spot/buildenv/debian-i386:stable
     - vol=spot-stable-$CI_COMMIT_SHA
     - docker volume create $vol
     - exitcode=0
     - docker run --rm=true -v $vol:/build/result registry.lrde.epita.fr/spot-debuild:stable ./build-spot.sh $CI_COMMIT_REF_NAME -j${NBPROC-1} || exitcode=$?
-    - docker run --rm=true -v $vol:/build/result registry.lrde.epita.fr/spot-debuild-i386:stable ./bin-spot.sh -j${NBPROC-1} || exitcode=$?
     - docker run -v $vol:/build/result --name helper-$vol registry.lrde.epita.fr/spot-debuild:stable true || exitcode=$?
     - docker cp helper-$vol:/build/result _build_stable || exitcode=$?
     - docker rm helper-$vol || exitcode=$?
@@ -192,6 +191,36 @@ debpkg-stable:
     - exit $exitcode
   artifacts:
     when: always
+    expire_in: 1 week
+    paths:
+      - _build_stable/
+
+debpkg-stable-i386:
+  stage: build2
+  only:
+    - /-deb$/
+    - master
+    - next
+    - stable
+  tags: ["x86"]
+  needs: ["debpkg-stable"]
+  script:
+    - docker pull gitlab-registry.lrde.epita.fr/spot/buildenv/debian-i386:stable
+    - vol=spot-stable-$CI_COMMIT_SHA
+    - docker volume create $vol
+    - exitcode=0
+    - docker create -v $vol:/build/result --name helper-$vol registry.lrde.epita.fr/spot-debuild-i386:stable ./bin-spot.sh -j${NBPROC-1} || exitcode=$?
+    - docker cp _build_stable/. helper-$vol:/build/result || exitcode=$?
+    - rm -rf _build_stable
+    - docker start -a helper-$vol || exitcode=$?
+    - docker cp helper-$vol:/build/result _build_stable || exitcode=$?
+    - docker rm helper-$vol || exitcode=$?
+    - docker volume rm $vol || exitcode=$?
+    - ls -l _build_stable
+    - exit $exitcode
+  artifacts:
+    when: always
+    expire_in: 1 week
     paths:
       - _build_stable/
 
@@ -206,9 +235,34 @@ debpkg-unstable:
     - vol=spot-unstable-$CI_COMMIT_SHA
     - docker volume create $vol
     - exitcode=0
-    - docker run --rm=true -v $vol:/build/result registry.lrde.epita.fr/spot-debuild ./build-spot.sh $CI_COMMIT_REF_NAME -j${NBPROC-1} || exitcode=$?
-    - docker run --rm=true -v $vol:/build/result registry.lrde.epita.fr/spot-debuild-i386 ./bin-spot.sh -j${NBPROC-1} || exitcode=$?
-    - docker run -v $vol:/build/result --name helper-$vol registry.lrde.epita.fr/spot-debuild true || exitcode=$?
+    - docker run -v $vol:/build/result --name helper-$vol registry.lrde.epita.fr/spot-debuild ./build-spot.sh $CI_COMMIT_REF_NAME -j${NBPROC-1} || exitcode=$?
+    - docker cp helper-$vol:/build/result _build_unstable || exitcode=$?
+    - docker rm helper-$vol || exitcode=$?
+    - docker volume rm $vol || exitcode=$?
+    - ls -l _build_unstable
+    - exit $exitcode
+  artifacts:
+    when: always
+    expire_in: 1 week
+    paths:
+      - _build_unstable/
+
+debpkg-unstable-i386:
+  stage: build2
+  only:
+    - /-deb$/
+    - next
+  tags: ["x86"]
+  needs: ["debpkg-unstable"]
+  script:
+    - docker pull gitlab-registry.lrde.epita.fr/spot/buildenv/debian-i386
+    - vol=spot-unstable-$CI_COMMIT_SHA
+    - docker volume create $vol
+    - exitcode=0
+    - docker create -v $vol:/build/result --name helper-$vol registry.lrde.epita.fr/spot-debuild-i386 ./bin-spot.sh -j${NBPROC-1} || exitcode=$?
+    - docker cp _build_unstable/. helper-$vol:/build/result || exitcode=$?
+    - rm -rf _build_unstable
+    - docker start -a helper-$vol || exitcode=$?
     - docker cp helper-$vol:/build/result _build_unstable || exitcode=$?
     - docker rm helper-$vol || exitcode=$?
     - docker volume rm $vol || exitcode=$?
@@ -216,6 +270,7 @@ debpkg-unstable:
     - exit $exitcode
   artifacts:
     when: always
+    expire_in: 1 week
     paths:
       - _build_unstable/
 
@@ -238,6 +293,7 @@ rpm-pkg:
     - mv ~/rpmbuild/RPMS/x86_64/*.rpm .
   artifacts:
     when: always
+    expire_in: 1 week
     paths:
       - ./*.rpm
 
@@ -261,7 +317,7 @@ publish-stable:
     - dput
   stage: publish
   dependencies:
-    - debpkg-stable
+    - debpkg-stable-i386
   script:
     - cd _build_stable
     - ls -l
@@ -277,7 +333,7 @@ publish-unstable:
     - dput
   stage: publish
   dependencies:
-    - debpkg-unstable
+    - debpkg-unstable-i386
   script:
     - cd _build_unstable
     - ls -l