>>> Emerging (1 of 84) dev-libs/nspr-4.6.1-r2 to /
Traceback (most recent call last):
  File "/usr/bin/emerge", line 4049, in ?
    emerge_main()
  File "/usr/bin/emerge", line 4044, in emerge_main
    myopts, myaction, myfiles, spinner)
  File "/usr/bin/emerge", line 3584, in action_build
    mergetask.merge(pkglist, favorites, mtimedb)
  File "/usr/bin/emerge", line 2048, in merge
    prev_mtimes=ldpath_mtimes)
  File "/usr/lib/portage/pym/portage.py", line 2899, in doebuild
    if need_distfiles and not fetch(
  File "/usr/lib/portage/pym/portage.py", line 2102, in fetch
    verified_ok, reason = portage_checksum.verify_all(
  File "/usr/lib/portage/pym/portage_checksum.py", line 104, in verify_all
    myhash = perform_checksum(filename, x, calc_prelink=calc_prelink)[0]
  File "/usr/lib/portage/pym/portage_checksum.py", line 144, in perform_checksum
    myhash, mysize = hashfunc_map[hashname](myfilename)
  File "/usr/lib/portage/pym/portage_checksum.py", line 30, in md5hash
    return fchksum.fmd5t(filename)
IOError: [Errno 5] Input/output error: '/usr/portage/distfiles/nspr-4.6.1.tar.gz'