[...]

No conditional flags passed
from available:
--with   :	 tests
--without:	
Available branches: master
Searching for tag auto/ti/protobuf-c-1.3.1-1...
Searching for tag auto/ti/protobuf-c-1_3_1-1...
--2018-10-22 10:43:38--  http://distfiles.pld-linux.org/distfiles/by-md5/a/b/ab3aa79312ed7b1fca401c8682e3aa7a/protobuf-c-1.3.1.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: 128705 (126K) [application/x-gzip]
Saving to: 'protobuf-c-1.3.1.tar.gz'
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2018-10-22 10:43:38 (1.01 MB/s) - 'protobuf-c-1.3.1.tar.gz' saved [128705/128705]
warning: Could not canonicalize hostname: giant
Building target platforms: i686-linux
Wrote: /home/users/builder/rpm/SRPMS/protobuf-c-1.3.1-1.src.rpm
exit status 0
Tagging with prefix: auto/ti/
Already on 'master'
No conditional flags passed
from available:
--with   :	 tests
--without:	
Writing git revision for tag auto/ti/protobuf-c-1.3.1-1
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.45284
+ umask 022
+ cd /home/users/builder/rpm/BUILD
+ rm -rf protobuf-c-1.3.1
Begin-TLD-Builder-Info
Build-Time: user:0.72s sys:0.14s real:2.34s (faults io:0 non-io:89483)
Files queued for ftp:
    134199 protobuf-c-1.3.1-1.src.rpm
       188 protobuf-c-1.3.1-1.src.rpm.uploadinfo
End-TLD-Builder-Info