Folks, I think this bug should be cleaned a little. So IMO: there are three issues which were linked (try to link) to this single bug:

1. Not critical as Matt said "ERROR Unable to read YAML: /etc/fuel/astute.yaml" and he created the related bug https://bugs.launchpad.net/fuel/+bug/1567307

2. issue happened in builds 470-474:
2016-04-04 01:17:13,761 - INFO environment.py:688 -- Result of "yum clean expire-cache; yum update -y" command on master node: {'exit_code': 1, 'stderr': ['\n', '\n', ' One of the configured repositories failed (Unknown),\n', " and yum doesn't have enough cached data to continue. At this point the only\n", ' safe thing yum can do is fail. There are a few ways to work "fix" this:\n', '\n', '     1. Contact the upstream for the repository and get them to fix the problem.\n', '\n', '     2. Reconfigure the baseurl/etc. for the repository, to point to a working\n', '        upstream. This is most often useful if you are using a newer\n', '        distribution release than is supported by the repository (and the\n', '        packages for the previous distribution release still work).\n', '\n', "     3. Disable the repository, so yum won't use it by default. Yum will then\n", '        just ignore the repository until you permanently enable it again or use\n', '        --enablerepo for temporary usage:\n', '\n', '            yum-config-manager --disable <repoid>\n', '\n', '     4. Configure the failing repository to be skipped, if it is unavailable.\n', '        Note that yum will try to contact the repo. when it runs most commands,\n', '        so will have to try and fail each time (and thus. yum will be be much\n', '        slower). If it is a very temporary problem though, this is often a nice\n', '        compromise:\n', '\n', '            yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true\n', '\n', 'Cannot find a valid baseurl for repo: mos9.0-security/7\n'], 'stdout': ['Loaded plugins: fastestmirror, priorities\n', 'Cleaning repos: 9.0_auxiliary mos mos9.0-security mos9.0-updates nailgun\n', '              : temporary-0\n', '7 metadata files removed\n', 'Loaded plugins: fastestmirror, priorities\n', 'Could not retrieve mirrorlist http://mirror.fuel-infra.org/mos-repos/centos/mos9.0-centos7/mos-mirrors-security.txt error was\n', '14: HTTP Error 404 - Not Found\n', 'Could not retrieve mirrorlist http://mirror.fuel-infra.org/mos-repos/centos/mos9.0-centos7/mos-mirrors-updates.txt error was\n', '14: HTTP Error 404 - Not Found\n', 'Loading mirror speeds from cached hostfile\n']}

IMO it's related to https://bugs.launchpad.net/fuel/+bug/1563870 and it was fixed, so no such issues should happen again
but I propose to update bug number on builds  470-474

3) issue happened in build 503, 510. As Matt said:
Error: Package: fuel-10.0.0-1.mos6330.noarch (temporary)
           Requires: fuel-provisioning-scripts >= 10.0.0
           Installed: fuel-provisioning-scripts-9.0.0-1.mos8602.noarch (@mos)
               fuel-provisioning-scripts = 9.0.0-1.mos8602
           Available: fuel-provisioning-scripts-8.0.0-1.mos8183.noarch (temporary)
               fuel-provisioning-scripts = 8.0.0-1.mos8183
           Available: fuel-provisioning-scripts-8.0.0-1.mos8253.noarch (temporary)
               fuel-provisioning-scripts = 8.0.0-1.mos8253

I guess this is because of mirror:
http://mirror.seed-cz1.fuel-infra.org/mos-repos/centos/mos9.0-centos7/os/x86_64/Packages/
has higher priority and it contains old fuel packages

To summarize:
- Build team should remove old fuel packages from
http://mirror.seed-cz1.fuel-infra.org/mos-repos/centos/mos9.0-centos7/os/x86_64/Packages/

- CI team and QA team should discuss how  system test should work:
* why do we need EXTRA_RPM_REPOS, etc