gdebi package missed dependence

After installation gdebi inside chroot in pbuilder, i get following error

/usr/bin/gdebi --quiet --apt-line ./libwnck3_3.4.3-99linvinus1.dsc
Traceback (most recent call last):
  File "/usr/bin/gdebi", line 84, in <module>
    if not debi.open(args[0]):
  File "/usr/share/gdebi/GDebi/GDebiCli.py", line 73, in open
    "Debian binary package" in Popen(["file", file], stdout=PIPE).communicate()[0]):
  File "/usr/lib/python2.7/subprocess.py", line 679, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1259, in _execute_child
    raise child_exception

gdebi use "/usr/bin/file" command to identify file, but package "file" not listed in package dependencies.
I suppose that this is mistake.

i'm use following command to install gdebi
 /usr/bin/apt-get install -y gdebi-core --no-install-recommends

the problem appear in precise and quantal
gdebi-core 0.8.5ubuntu1