Making nethserver-fetchmail rpms

Continuing the discussion from NethServer v7-alpha2:

I'm following the howto, and after

make-rpms nethserver-fetchmail.spec

I obtain

prep-sources [INFO] source0 git archive: nethserver-fetchmail-1.1.5.tar.gz
INFO: mock.py version 1.2.13 starting (python version = 2.7.5)...
Start: init plugins
INFO: selinux enabled
Finish: init plugins
Start: run
INFO: Start(nethserver-fetchmail.spec)  Config(nethserver-6.7-x86_64)
Start: clean chroot
Finish: clean chroot
Start: chroot init
INFO: calling preinit hooks
INFO: enabled root cache
INFO: enabled yum cache
Start: cleaning yum metadata
Finish: cleaning yum metadata
Mock Version: 1.2.13
INFO: Mock Version: 1.2.13
ERROR: Exception(nethserver-fetchmail.spec) Config(nethserver-6.7-x86_64) 0 minutes 0 seconds
INFO: Results and/or logs in: .
INFO: Cleaning up build root ('cleanup_on_failure=True')
Start: clean chroot
Finish: clean chroot
ERROR: [Errno 21] Is a directory: '/etc/localtime'
Traceback (most recent call last):
  File "/usr/sbin/mock", line 833, in <module>
    main()
  File "/usr/lib/python2.7/site-packages/mockbuild/trace_decorator.py", line 84, in trace
    result = func(*args, **kw)
  File "/usr/sbin/mock", line 649, in main
    run_command(options, args, config_opts, commands, buildroot, state)
  File "/usr/lib/python2.7/site-packages/mockbuild/trace_decorator.py", line 84, in trace
    result = func(*args, **kw)
  File "/usr/sbin/mock", line 732, in run_command
    do_buildsrpm(config_opts, commands, buildroot, options, args)
  File "/usr/lib/python2.7/site-packages/mockbuild/trace_decorator.py", line 84, in trace
    result = func(*args, **kw)
  File "/usr/sbin/mock", line 511, in do_buildsrpm
    cmd=cmd, post=None, clean=clean)
  File "/usr/lib/python2.7/site-packages/mockbuild/trace_decorator.py", line 84, in trace
    result = func(*args, **kw)
  File "/usr/sbin/mock", line 439, in rebuild_generic
    commands.init(prebuild=not config_opts.get('short_circuit'))
  File "/usr/lib/python2.7/site-packages/mockbuild/trace_decorator.py", line 84, in trace
    result = func(*args, **kw)
  File "/usr/lib/python2.7/site-packages/mockbuild/backend.py", line 122, in init
    self.buildroot.initialize(**kwargs)
  File "/usr/lib/python2.7/site-packages/mockbuild/trace_decorator.py", line 84, in trace
    result = func(*args, **kw)
  File "/usr/lib/python2.7/site-packages/mockbuild/buildroot.py", line 85, in initialize
    self._init(prebuild=prebuild, do_log=do_log)
  File "/usr/lib/python2.7/site-packages/mockbuild/trace_decorator.py", line 84, in trace
    result = func(*args, **kw)
  File "/usr/lib/python2.7/site-packages/mockbuild/buildroot.py", line 142, in _init
    self._setup_timezone()
  File "/usr/lib/python2.7/site-packages/mockbuild/trace_decorator.py", line 84, in trace
    result = func(*args, **kw)
  File "/usr/lib/python2.7/site-packages/mockbuild/buildroot.py", line 221, in _setup_timezone
    self._copy_config('localtime')
  File "/usr/lib/python2.7/site-packages/mockbuild/trace_decorator.py", line 84, in trace
    result = func(*args, **kw)
  File "/usr/lib/python2.7/site-packages/mockbuild/buildroot.py", line 197, in _copy_config
    shutil.copy2(orig_conf_file, etcdir)
  File "/usr/lib64/python2.7/shutil.py", line 130, in copy2
    copyfile(src, dst)
  File "/usr/lib64/python2.7/shutil.py", line 82, in copyfile
    with open(src, 'rb') as fsrc:
IOError: [Errno 21] Is a directory: '/etc/localtime'

Any hint?