Random failures probably when archiving results: "ERROR: Build failed: API error (404): No such container"

Hi, I am using the latest gitlab, 8.8.1 and gitlab runner 1.2.0 (3a4fcd4) Since we upgraded from 1.1.2 to 1.2.0, we get random failures after our tests run:

gitlab-ci-multi-runner 1.2.0 (3a4fcd4)
Using Docker executor with image ... ...
Pulling docker image .../thorn_solr:latest ...
WARNING: Cannot pull the latest version of image .../thorn_solr:latest : Error: image .../thorn_solr not found
WARNING: Locally found image will be used instead.
Starting service .../thorn_solr:latest ...
Waiting for services to be up and running...
Pulling docker image .../centos-thornlighting ...
Running on runner-03e2d752-project-36-concurrent-0 via ci2...
Cloning repository...
Cloning into '.../buildout.tl-website'...
Checking out 7e6d1a8a as master...
Checking cache for .../master...
Downloading artifacts for build_code (37170)...
Downloading artifacts from coordinator... ok        id=37170 responseStatus=200 OK token=9194009b
Now using node v5.10.1 (npm v3.8.3)
$ bin/jenkins-test -s zlag.pdb
Running zlag.pdb.testing.zlag.pdb:Functional tests:
  Set up zlag.pdb.testing.SqliteLayer in 1 minutes 17.987 seconds.
  Set up plone.testing.zca.LayerCleanup in 0.000 seconds.
  Set up plone.testing.z2.Startup in 0.152 seconds.
  Set up plone.app.testing.layers.PloneFixture in 6.719 seconds.
  Set up zlag.pdb.testing.zlag.pdb.solr_layer in 0.450 seconds.
  Set up zlag.pdb.testing.PatchedZAMQPLayer in 0.002 seconds.
  Set up zlag.pdb.testing.ZLAGPDBLayer Could not install product Products.DateRecurringIndex
in 11.948 seconds.
  Set up zlag.pdb.testing.zlag.pdb:Functional in 0.000 seconds.
  Ran 17 tests with 0 failures, 0 errors and 0 skipped in 3 minutes 24.600 seconds.
Running zlag.pdb.testing.zlag.pdb:FunctionalSampledata tests:
  Tear down zlag.pdb.testing.zlag.pdb:Functional in 0.000 seconds.
  Set up zlag.pdb.testing.SampledataLayer in 7.468 seconds.
  Set up zlag.pdb.testing.zlag.pdb:FunctionalSampledata in 0.000 seconds.
  Ran 40 tests with 0 failures, 0 errors and 0 skipped in 4.605 seconds.
Running zlag.pdb.testing.zlag.pdb:Integration tests:
  Tear down zlag.pdb.testing.zlag.pdb:FunctionalSampledata in 0.000 seconds.
  Tear down zlag.pdb.testing.SampledataLayer in 1.561 seconds.
  Set up zlag.pdb.testing.zlag.pdb:Integration in 0.000 seconds.
  Ran 13 tests with 0 failures, 0 errors and 0 skipped in 9.136 seconds.
Running zlag.pdb.testing.zlag.pdb:IntegrationSampledata tests:
  Tear down zlag.pdb.testing.zlag.pdb:Integration in 0.000 seconds.
  Set up zlag.pdb.testing.SampledataLayer in 6.118 seconds.
  Set up zlag.pdb.testing.zlag.pdb:IntegrationSampledata in 0.000 seconds.
  Ran 3 tests with 0 failures, 0 errors and 0 skipped in 11.775 seconds.
Running zope.testrunner.layer.UnitTests tests:
  Tear down zlag.pdb.testing.zlag.pdb:IntegrationSampledata in 0.000 seconds.
  Tear down zlag.pdb.testing.SampledataLayer in 1.658 seconds.
  Tear down zlag.pdb.testing.ZLAGPDBLayer in 0.015 seconds.
  Tear down zlag.pdb.testing.SqliteLayer in 0.000 seconds.
  Tear down zlag.pdb.testing.zlag.pdb.solr_layer in 0.004 seconds.
  Tear down zlag.pdb.testing.PatchedZAMQPLayer in 0.000 seconds.
  Tear down plone.app.testing.layers.PloneFixture in 0.057 seconds.
  Tear down plone.testing.z2.Startup in 0.005 seconds.
  Tear down plone.testing.zca.LayerCleanup in 0.003 seconds.
  Set up zope.testrunner.layer.UnitTests in 0.000 seconds.
  Ran 3 tests with 0 failures, 0 errors and 0 skipped in 0.001 seconds.
Tearing down left over layers:
  Tear down zope.testrunner.layer.UnitTests in 0.000 seconds.
Total: 76 tests, 0 failures, 0 errors and 0 skipped in 5 minutes 45.742 seconds.
Now using node v5.10.1 (npm v3.8.3)

ERROR: Build failed: API error (404): No such container: aefcba02e5c6064a4afe4f65c9b6d6625d38211a9674fec08e88facb2482714e

When triggering the build again, it works as expected, the output starting with Now using node v5.10.1...:

Now using node v5.10.1 (npm v3.8.3)
Creating cache test:zlag.pdb/master...
WARNING: .cache/: no matching files                
WARNING: dev/bower_components/: no matching files  
WARNING: download-cache/: no matching files        
eggs/: found 45698 matching files                  
WARNING: node_modules/: no matching files          
WARNING: wheels/: no matching files                

Build succeeded

The container id changes each time. I can't see the id when running docker ps -a on the server there the runner is running. I also have network timeouts from time to time, maybe this could be related. But I can't tell from the output.