[...]

building SRPM using: cd rpm/packages; nice -n 0 ./builder -nu -nm --nodeps --http --define '_tld_builder 1' -bs  -r HEAD    mdadm.spec 2>&1
Cloning into 'mdadm'...
13309750e9b2bcf70465d879297617c7cd5e9cca
Already on 'master'
Your branch is up-to-date with 'origin/master'.
Already up-to-date.
No conditional flags passed
from available:
--with   :	 dietlibc initrd
--without:	 tests
Available branches: master
--2017-01-04 13:33:01--  http://df.tld-linux.org/distfiles/by-md5/0/4/04b8b21f637540350f8517c7e68d3c63/mdadm-3.4.tar.xz
Resolving df.tld-linux.org (df.tld-linux.org)... 46.4.78.55
Connecting to df.tld-linux.org (df.tld-linux.org)|46.4.78.55|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 422704 (413K) [application/x-xz]
Saving to: 'mdadm-3.4.tar.xz'
     0K .......... .......... .......... .......... .......... 12% 18.3M 0s
    50K .......... .......... .......... .......... .......... 24%  120M 0s
   100K .......... .......... .......... .......... .......... 36% 34.1M 0s
   150K .......... .......... .......... .......... .......... 48% 82.4M 0s
   200K .......... .......... .......... .......... .......... 60%  173M 0s
   250K .......... .......... .......... .......... .......... 72% 45.0M 0s
   300K .......... .......... .......... .......... .......... 84%  188M 0s
   350K .......... .......... .......... .......... .......... 96%  174M 0s
   400K .......... ..                                         100%  110M=0.007s
2017-01-04 13:33:04 (56.6 MB/s) - 'mdadm-3.4.tar.xz' saved [422704/422704]
Building target platforms: i686-linux
Wrote: /home/users/builder/rpm/SRPMS/mdadm-3.4-1.src.rpm
exit status 0
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.46868
+ umask 022
+ cd /home/users/builder/rpm/BUILD
+ rm -rf mdadm-3.4
Begin-TLD-Builder-Info
Build-Time: user:0.68s sys:0.19s real:21.80s (faults io:155 non-io:105079)
Files queued for ftp:
    433133 mdadm-3.4-1.src.rpm
End-TLD-Builder-Info