mock-1.2.14 is bugfix release, but some bugfix may be interesting for you:

• –new-chroot now works on rhel7
• create tmpfs with unlimited inodes RHBZ#1266453 - otherwise architectures with large pages (e.g. PPC64) can use only fraction of the tmpfs capacity.
• Add %(resultdir) placeholder for sign plugin. RHBZ#1272123
• use –setopt=deltarpm=false as default value for dnf_common_opts RHBZ#1281355
• fixed issue with /home mount on nfs RHBZ#1281369