[...]

ag auto/ti/xen-4.10.0-0.1
On detached HEAD. Use -r BRANCHNAME to override
error: Macro %_builddir has empty body
error: Macro %_builddir has empty body
Executing(--clean): env -i TMP=/home/users/builder/tmp HOME=/home/users/builder PATH=/bin:/usr/bin:/usr/sbin:/sbin:/usr/X11R6/bin TMPDIR=/home/users/builder/tmp  /bin/sh -e /home/users/builder/tmp/rpm-tmp.79509
+ umask 022
+ cd /home/users/builder/rpm/BUILD
+ rm -rf xen-4.10.0
Begin-TLD-Builder-Info
Build-Time: user:2.65s sys:0.57s real:8.52s (faults io:99 non-io:463135)
Files queued for ftp:
  44982684 xen-4.10.0-0.1.src.rpm
       184 xen-4.10.0-0.1.src.rpm.uploadinfo
End-TLD-Builder-Info