nixpkgs/pkgs/build-support/fetchcvs/builder.sh

source $stdenv/setup

# creating the export drictory and checking out there only to be able to
# move the content without the root directory into $out ...
# cvs -f -d "$url" export $tag -d "$out" "$module"
# should work (but didn't - got no response on #cvs)
# See als man Page for those options

ensureDir $out export
set -x
if [ -n "$tag" ]; then
  tag="-r $tag"
else
  if [ -n "$date" ]; then
    tag="-D $date"
  else
    tag="-D NOW"
  fi
fi
cd export; cvs -f -d "$url" export $tag "$module"
mv */* $out

stopNest