Steps to Reproduce:

non_exist_ksversion = 'RHELuhrnd'

Run API command:
buildImageOz(package_name, version, [arches], build_target, image_repo, opts={'ksurl': ksurl, 'ksversion': non_exist_ksversion, 'kickstart': kickstart, 'repo': [image_repo], 'distro': distro, 'format': [format_image], 'disk_size': disk_size, 'factory_parameter': [('create_docker_metadata', 'False','--can-fail=')], 'optional_arches': ''}, priority=None)

parameters:
Arches: x86_64
Build Target: build-target-rhel-7.4-build-42jh
Installation Tree: http://download-node-02.eng.bos.redhat.com/composes/released/RHEL-7/7.4/Server/x86_64/os/
Options:
kickstart = rhel-7.4-server-docker.ks
disk_size = 10
ksversion = RHELuhrnd
format = docker
repo = http://download-node-02.eng.bos.redhat.com/composes/released/RHEL-7/7.4/Server/x86_64/os/
optional_arches =
ksurl = git://git.app.eng.bos.redhat.com/spin-kickstarts.git?rhel7#HEAD
distro = RHEL-7.4
factory_parameter = ['create_docker_metadata', 'False', '--can-fail=']

Actual result:

Traceback (most recent call last):
File "/usr/lib/python2.7/site-packages/koji/daemon.py", line 1244, in runTask
response = (handler.run(),)
File "/usr/lib/python2.7/site-packages/koji/tasks.py", line 307, in run
return koji.util.call_with_argcheck(self.handler, self.params, self.opts)
File "/usr/lib/python2.7/site-packages/koji/util.py", line 216, in call_with_argcheck
return func(args, *kwargs)
File "/usr/sbin/kojid", line 4098, in handler
ks = self.prepareKickstart(kspath, inst_tree)
File "/usr/sbin/kojid", line 3496, in prepareKickstart
ks = self.readKickstart(kspath)
File "/usr/sbin/kojid", line 3470, in readKickstart
version = ksparser.version.makeVersion(self.opts['ksversion'])
File "/usr/lib/python2.7/site-packages/pykickstart/version.py", line 200, in makeVersion
cl = returnClassForVersion(version)
File "/usr/lib/python2.7/site-packages/pykickstart/version.py", line 178, in returnClassForVersion
version = stringToVersion(version)
File "/usr/lib/python2.7/site-packages/pykickstart/version.py", line 132, in stringToVersion
raise KickstartVersionError(_("Unsupported version specified: %s") % s)
KickstartVersionError: Unsupported version specified: RHELuhrnd

Expected result:

Should be returning a GenericError message that ksversion does not exist.