[...]

builder: SMP make flags are set to -j2
Cloning into 'json-c'...
0d773959b327eb7922213d872e97fa60226f182b
Already on 'master'
Your branch is up-to-date with 'origin/master'.
Already up-to-date.
Available branches: master
Searching for tag auto/ti/json-c-0.12-2...
Searching for tag auto/ti/json-c-0_12-2...
--2015-07-15 15:24:38--  http://distfiles.pld-linux.org/distfiles/by-md5/3/c/3ca4bbb881dfc4017e8021b5e0a8c491/json-c-0.12.tar.gz
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: 501419 (490K) [application/x-gzip]
Saving to: 'json-c-0.12.tar.gz'
     0K .......... .......... .......... .......... .......... 10%  893K 0s
    50K .......... .......... .......... .......... .......... 20% 1.67M 0s
   100K .......... .......... .......... .......... .......... 30% 1.73M 0s
   150K .......... .......... .......... .......... .......... 40% 1.81M 0s
   200K .......... .......... .......... .......... .......... 51% 11.5M 0s
   250K .......... .......... .......... .......... .......... 61% 1.93M 0s
   300K .......... .......... .......... .......... .......... 71% 11.6M 0s
   350K .......... .......... .......... .......... .......... 81% 11.5M 0s
   400K .......... .......... .......... .......... .......... 91% 2.22M 0s
   450K .......... .......... .......... .........            100% 11.0M=0.2s
2015-07-15 15:24:38 (2.34 MB/s) - 'json-c-0.12.tar.gz' saved [501419/501419]
warning: Could not canonicalize hostname: giant
Building target platforms: i686-linux
Wrote: /home/users/builder/rpm/SRPMS/json-c-0.12-2.src.rpm
exit status 0
Tagging with prefix: auto/ti/
Already on 'master'
Writing git revision for tag auto/ti/json-c-0.12-2
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.82878
+ umask 022
+ cd /home/users/builder/rpm/BUILD
+ rm -rf json-c-0.12
Begin-PLD-Builder-Info
Build-Time: user:2.60s sys:1.11s real:14.66s (faults io:1 non-io:175942)
Files queued for ftp:
    506529 json-c-0.12-2.src.rpm
       183 json-c-0.12-2.src.rpm.uploadinfo
End-PLD-Builder-Info