[...]

building SRPM using: cd rpm/packages; nice -n 0 ./builder -nu -nm --nodeps --http -bs  -r HEAD  -Tp auto/ti/ -tt  libass.spec 2>&1
builder: SMP make flags are set to -j2
Cloning into 'libass'...
3ad622371def32702aafb9767d0d8df0b364b41d
Already on 'master'
Already up-to-date.
Available branches: master
Searching for tag auto/ti/libass-0.10.2-1...
Searching for tag auto/ti/libass-0_10_2-1...
--2014-07-30 05:31:33--  http://distfiles.pld-linux.org/distfiles/by-md5/c/e/ce672ed5629c9708b3401b976f516744/libass-0.10.2.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: 278244 (272K) [application/octet-stream]
Saving to: 'libass-0.10.2.tar.xz'
     0K .......... .......... .......... .......... .......... 18%  156K 1s
    50K .......... .......... .......... .......... .......... 36%  130K 1s
   100K .......... .......... .......... .......... .......... 55%  130K 1s
   150K .......... .......... .......... .......... .......... 73%  142K 1s
   200K .......... .......... .......... .......... .......... 92%  142K 0s
   250K .......... .......... .                               100%  136K=2.0s
2014-07-30 05:31:35 (139 KB/s) - 'libass-0.10.2.tar.xz' saved [278244/278244]
Building target platforms: i686-linux
Wrote: /home/users/builder/rpm/SRPMS/libass-0.10.2-1.src.rpm
exit status 0
Tagging with prefix: auto/ti/
Version: 0.10.2
Release: 1
tag: auto/ti/libass-0.10.2-1
Searching for tag auto/ti/libass-0.10.2-1...
To ssh://git@git.pld-linux.org/packages/libass
 * [new tag]         auto/ti/libass-0.10.2-1 -> auto/ti/libass-0.10.2-1
error: Macro %_builddir has empty body
error: Macro %_builddir has empty body
Executing(--clean):  env -i TMP=/home/users/builder/tmp PATH=/bin:/usr/bin:/usr/sbin:/sbin:/usr/X11R6/bin HOME=/home/users/builder TMPDIR=/home/users/builder/tmp  /bin/sh -e /home/users/builder/tmp/rpm-tmp.72606
+ umask 022
+ cd /home/users/builder/rpm/BUILD
+ rm -rf libass-0.10.2
Begin-PLD-Builder-Info
Build-Time: user:2.32s sys:1.01s real:8.80s (faults io:0 non-io:149168)
Files queued for ftp:
    283037 libass-0.10.2-1.src.rpm
       185 libass-0.10.2-1.src.rpm.uploadinfo
End-PLD-Builder-Info