fedup Fedora 20 to 21 failing on Linode

Has anyone tried to update a Fedora 20 Linode to Fedora 21, successfully or otherwise? I have done this successfully on a local install of Fedora 20, but the first Linode I tried failed with the following error.

# fedup --network 21 --product=nonproduct          
setting up repos...
... 
testing upgrade transaction
rpm transaction 100% [===========================================================================================================================================]
rpm install 100% [===============================================================================================================================================]
setting up system for upgrade
Traceback (most recent call last):
  File "/usr/bin/fedup", line 286, in <module>
    main(args)
  File "/usr/bin/fedup", line 223, in main
    prep_boot(kernel, initrd)
  File "/usr/lib/python2.7/site-packages/fedup/sysprep.py", line 168, in prep_boot
    customize_initrd(initrd)
  File "/usr/lib/python2.7/site-packages/fedup/sysprep.py", line 139, in customize_initrd
    wantfiles = fnmatch.filter(curimg, "etc/*")
  File "/usr/lib64/python2.7/fnmatch.py", line 58, in filter
    for name in names:
  File "/usr/lib/python2.7/site-packages/fedup/boot.py", line 108, in __iter__
    return iter(self.listfiles())
  File "/usr/lib/python2.7/site-packages/fedup/boot.py", line 74, in listfiles
    self._files = self.cpio("--list").splitlines()
  File "/usr/lib/python2.7/site-packages/fedup/boot.py", line 69, in cpio
    stdin=self.decomp().stdout)
  File "/usr/lib/python2.7/site-packages/fedup/boot.py", line 60, in decomp
    self._decomp = decomp_cmd(self.img)
  File "/usr/lib/python2.7/site-packages/fedup/util.py", line 107, in decomp_cmd
    header = open(filename, 'rb').read(6)
IOError: [Errno 2] No such file or directory: '/boot/initramfs-3.15.4-x86_64-linode45.img'</module>