When trying to compose f23 we get the following failure
2015-07-21 04:35:28 [ERROR   ] Extended traceback in: /mnt/koji/compose/rawhide/Fedora-23-20150721.n.0/logs/global/traceback.global.log
2015-07-21 04:35:28 [CRITICAL] Compose failed: /mnt/koji/compose/rawhide/Fedora-23-20150721.n.0
Traceback (most recent call last):
  File "/bin/pungi-koji", line 326, in <module>
    main()
  File "/bin/pungi-koji", line 180, in main
    run_compose(compose)
  File "/bin/pungi-koji", line 254, in run_compose
    buildinstall_phase.stop()
  File "/usr/lib/python2.7/site-packages/pungi/phases/base.py", line 68, in stop
    self.pool.stop()
  File "/usr/lib/python2.7/site-packages/kobo/threads.py", line 65, in run
    self.process(item, num)
  File "/usr/lib/python2.7/site-packages/pungi/phases/buildinstall.py", line 350, in process
    raise RuntimeError("Runroot task failed: %s. See %s for more details." % (output["task_id"], log_file))
RuntimeError: Runroot task failed: 10422030. See /mnt/koji/compose/rawhide/Fedora-23-20150721.n.0/logs/x86_64/buildinstall.x86_64.log for more details.

real    136m26.701s
user    82m46.800s
sys     6m53.530s
[root@compose-x86-01 pungi-fedora]# vim /mnt/koji/compose/rawhide/Fedora-23-20150721.n.0/logs/x86_64/buildinstall.x86_64.log

10422030
+ lorax --product=Fedora --version=23 --release=23 --source=file:///mnt/koji/compose/rawhide/Fedora-23-20150721.n.0/work/x86_64/repo --nomacboot --buildarch=x86_64 '--volid=Fedora-23 x86_64' /mnt/koji/compose/rawhide/Fedora-23-20150721.n.0/work/x86_64/buildinstall
2015-07-21 04:02:24,553: Added 'lorax-repo-0': file:///mnt/koji/compose/rawhide/Fedora-23-20150721.n.0/work/x86_64/repo
2015-07-21 04:02:24,554: Fetching metadata...
repo: downloading from remote: lorax-repo-0, _Handle: metalnk: None, mlist: None, urls ['file:///mnt/koji/compose/rawhide/Fedora-23-20150721.n.0/work/x86_64/repo'].
repo: using cache for: lorax-repo-0 
not found deltainfo for: lorax-repo-0
not found updateinfo for: lorax-repo-0
timer: sack setup: 42668 ms
Getting group metadata
Adding group file from repository: lorax-repo-0
timer: loading comps: 27 ms
2015-07-21 04:03:08,393: checking for root privileges
checking for root privileges
2015-07-21 04:03:08,393: checking the selinux mode
checking the selinux mode
2015-07-21 04:03:08,393: checking dnf base object
checking dnf base object
2015-07-21 04:03:08,393: setting up build architecture
setting up build architecture
2015-07-21 04:03:08,394: setting up build parameters
setting up build parameters
2015-07-21 04:03:08,395: installing runtime packages
installing runtime packages
2015-07-21 04:03:11,500: got release: fedora-release
got release: fedora-release
2015-07-21 04:03:11,556: running runtime-install.tmpl
running runtime-install.tmpl
2015-07-21 04:03:11,853: Looking for extra fedup-dracut packages...
Looking for extra fedup-dracut packages...
2015-07-21 04:03:12,121: installpkg *-fedup-dracut failed: no package matched
installpkg *-fedup-dracut failed: no package matched
2015-07-21 04:03:12,580: Checking dependencies
Checking dependencies
timer: depsolve: 15 ms
2015-07-21 04:03:12,607: 700 packages selected
700 packages selected
2015-07-21 04:03:12,617: Downloading packages
Downloading packages
2015-07-21 04:03:12,624: Preparing transaction from installation source
Preparing transaction from installation source
2015-07-21 04:03:13,153: The transaction process has ended abruptly: [Errno 2] No such file or directory: '/mnt/koji/compose/rawhide/Fedora-23-20150721.n.0/work/x86_64/repo/packages/fedora-release/23/0.15/noarch/fedora-release-23-0.15.noarch.rpm'
The transaction process has ended abruptly: [Errno 2] No such file or directory: '/mnt/koji/compose/rawhide/Fedora-23-20150721.n.0/work/x86_64/repo/packages/fedora-release/23/0.15/noarch/fedora-release-23-0.15.noarch.rpm'
2015-07-21 04:03:13,156: Transaction failed.
Transaction failed.
2015-07-21 04:03:13,156: template command error in runtime-install.tmpl:
template command error in runtime-install.tmpl:
2015-07-21 04:03:13,157:   run_pkg_transaction
  run_pkg_transaction
2015-07-21 04:03:14,764:   Exception: Transaction failed
  Exception: Transaction failed
Traceback (most recent call last):  
  File "/usr/sbin/lorax", line 315, in <module>
    main(sys.argv)
  File "/usr/sbin/lorax", line 203, in main
    remove_temp=True)
  File "/usr/lib/python3.4/site-packages/pylorax/__init__.py", line 263, in run
    rb.install()
  File "/usr/lib/python3.4/site-packages/pylorax/treebuilder.py", line 117, in install
    self._runner.run("runtime-install.tmpl")
  File "/usr/lib/python3.4/site-packages/pylorax/ltmpl.py", line 191, in run
    self._run(commands)
  File "/usr/lib/python3.4/site-packages/pylorax/ltmpl.py", line 210, in _run
    f(*args)
  File "/usr/lib/python3.4/site-packages/pylorax/ltmpl.py", line 572, in run_pkg_transaction
    raise Exception("Transaction failed")
Exception: Transaction failed


looking at the metadata

<package type="rpm">
  <name>fedora-release</name>
  <arch>noarch</arch>
  <version epoch="0" ver="23" rel="0.15"/>
  <checksum type="sha256" pkgid="YES">597a25f78e8f2bc23444a510458fa4a8969a27eb0f9cde056b2c1fbbea5b30c6</checksum>
  <summary>Fedora release files</summary>
  <description>Fedora release files such as various /etc/ files that define the release.</description>
  <packager>Fedora Project</packager>
  <url>http://fedoraproject.org</url>
  <time file="1436972725" build="1436972721"/>
  <size package="14772" installed="7757" archive="10720"/>
  <location xml:base="file:///mnt/koji/" href="packages/fedora-release/23/0.15/noarch/fedora-release-23-0.15.noarch.rpm"/>
  <format>
    <rpm:license>MIT</rpm:license>
    <rpm:vendor>Fedora Project</rpm:vendor>
    <rpm:group>System Environment/Base</rpm:group>
    <rpm:buildhost>arm04-builder02.arm.fedoraproject.org</rpm:buildhost>
    <rpm:sourcerpm>fedora-release-23-0.15.src.rpm</rpm:sourcerpm>
    <rpm:header-range start="4392" end="11144"/>
    <rpm:provides>
      <rpm:entry name="config(fedora-release)" flags="EQ" epoch="0" ver="23" rel="0.15"/>
      <rpm:entry name="fedora-release" flags="EQ" epoch="0" ver="23" rel="0.15"/>
      <rpm:entry name="fedora-release-nonproduct" flags="EQ" epoch="0" ver="23"/>
      <rpm:entry name="fedora-release-standard" flags="EQ" epoch="0" ver="22" rel="0.8"/>
      <rpm:entry name="redhat-release"/>
      <rpm:entry name="system-release"/>
      <rpm:entry name="system-release(23)"/>
    </rpm:provides>
    <rpm:requires>
      <rpm:entry name="/bin/sh"/>
      <rpm:entry name="fedora-repos(23)"/>
    </rpm:requires>
    <rpm:obsoletes>
      <rpm:entry name="fedora-release-nonproduct" flags="LE" epoch="0" ver="23" rel="0.3"/>
      <rpm:entry name="fedora-release-standard" flags="LT" epoch="0" ver="22" rel="0.8"/>
      <rpm:entry name="redhat-release"/>
    </rpm:obsoletes>
    <file>/etc/fedora-release</file>
    <file>/etc/issue</file>
    <file>/etc/issue.net</file>
    <file>/etc/os-release</file>
    <file>/etc/redhat-release</file>
    <file>/etc/system-release</file>
    <file>/etc/system-release-cpe</file>
  </format>
</package>


if dnf followed the xml:base it would have found the package correctly.