Sometimes it is just quicker to test the building of a CentOS package locally, than to wait for the OBS server to build it.
You also get a chance to search the BUILD directory for files that you might be missing.

I have written how to do this for Debian in an earlier post (see near the bottom):

See also how to install osc for all sorts of Linux distributions!

For CentOS, you do this:

cd /etc/yum.repos.d/
yum install osc build
osc -A checkout home:timotheus:branches:Kolab:Development
cd home:timotheus:branches:Kolab:Development/kolab-utils
osc build CentOS_6 x86_64 kolab-utils.spec --no-verify

Without the –no-verify parameter, you get errors like these:

/var/tmp/osbuild-packagecache/CentOS:6/release/x86_64/acl-2.2.49-6.el6.x86_64.rpm : public key not available
/var/tmp/osbuild-packagecache/CentOS:6/release/x86_64/attr-2.4.44-7.el6.x86_64.rpm : public key not available

By the way, you find the BUILDROOT in:

Build OBS packages locally for CentOS
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