[...]

No conditional flags passed
from available:
--with   :	
--without:	 apidocs static_libs
Available branches: master
Searching for tag auto/ti/libzen-0.4.37-1...
Searching for tag auto/ti/libzen-0_4_37-1...
--2018-08-31 21:24:22--  http://distfiles.pld-linux.org/distfiles/by-md5/c/2/c2538d08a8ba49790a7e0768d19693ff/libzen_0.4.37.tar.xz
Resolving distfiles.pld-linux.org (distfiles.pld-linux.org)... 193.239.45.41
Connecting to distfiles.pld-linux.org (distfiles.pld-linux.org)|193.239.45.41|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 114680 (112K) [application/octet-stream]
Saving to: 'libzen_0.4.37.tar.xz'
     0K .......... .......... .......... .......... .......... 44% 1.22M 0s
    50K .......... .......... .......... .......... .......... 89% 2.42M 0s
   100K .......... .                                          100%  293M=0.06s
2018-08-31 21:24:22 (1.81 MB/s) - 'libzen_0.4.37.tar.xz' saved [114680/114680]
Building target platforms: i686-linux
Wrote: /home/users/builder/rpm/SRPMS/libzen-0.4.37-1.src.rpm
exit status 0
Tagging with prefix: auto/ti/
Already on 'master'
No conditional flags passed
from available:
--with   :	
--without:	 apidocs static_libs
Writing git revision for tag auto/ti/libzen-0.4.37-1
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.50361
+ umask 022
+ cd /home/users/builder/rpm/BUILD
+ rm -rf ZenLib
Begin-TLD-Builder-Info
Build-Time: user:0.54s sys:0.05s real:1.83s (faults io:0 non-io:103490)
Files queued for ftp:
    120867 libzen-0.4.37-1.src.rpm
       185 libzen-0.4.37-1.src.rpm.uploadinfo
End-TLD-Builder-Info