INFO: mock.py version 1.4.3 starting (python version = 3.6.2)...
Start: init plugins
INFO: selinux disabled
Finish: init plugins
Start: run
INFO: Start(/var/tmp/grepcidr/grepcidr-2.0-1.fc26.art.src.rpm)  Config(fedora-15-i386)
Start: clean chroot
Finish: clean chroot
Start: chroot init
INFO: calling preinit hooks
INFO: enabled root cache
INFO: enabled yum cache
Start: cleaning yum metadata
Finish: cleaning yum metadata
INFO: enabled HW Info plugin
Mock Version: 1.4.3
INFO: Mock Version: 1.4.3
Start: yum install
ERROR: Exception(/var/tmp/grepcidr/grepcidr-2.0-1.fc26.art.src.rpm) Config(fedora-15-i386) 0 minutes 0 seconds
INFO: Results and/or logs in: /var/lib/mock/fedora-15-i386/result
ERROR: Command failed: 
 # /usr/bin/yum-deprecated --installroot /var/lib/mock/fedora-15-i386/root/ groupinstall buildsys-build
Yum command has been deprecated, use dnf instead.
See 'man dnf' and 'man yum2dnf' for more information.

There is no installed groups file.
Maybe run: yum groups mark convert (see man yum)
http://build/atomicorp/atomic-testing/fedora/15/i386/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found
Trying other mirror.


 One of the configured repositories failed (atomic),
 and yum doesn't have enough cached data to continue. At this point the only
 safe thing yum can do is fail. There are a few ways to work "fix" this:

     1. Contact the upstream for the repository and get them to fix the problem.

     2. Reconfigure the baseurl/etc. for the repository, to point to a working
        upstream. This is most often useful if you are using a newer
        distribution release than is supported by the repository (and the
        packages for the previous distribution release still work).

     3. Disable the repository, so yum won't use it by default. Yum will then
        just ignore the repository until you permanently enable it again or use
        --enablerepo for temporary usage:

            yum-config-manager --disable atomic-testing

     4. Configure the failing repository to be skipped, if it is unavailable.
        Note that yum will try to contact the repo. when it runs most commands,
        so will have to try and fail each time (and thus. yum will be be much
        slower). If it is a very temporary problem though, this is often a nice
        compromise:

            yum-config-manager --save --setopt=atomic-testing.skip_if_unavailable=true

failure: repodata/repomd.xml from atomic-testing: [Errno 256] No more mirrors to try.
http://build/atomicorp/atomic-testing/fedora/15/i386/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found