I'm trying this guide for having access to emerge on chromeos.

http://www.chromium.org/chromium-os/how-tos-and-troubleshooting/install-software-on-base-images

Unfortunately I always got the same error which is

$ sudo dev_install
Starting installation of developer packages.
First, we download the necessary files.
Downloading https://commondatastorage.googleapis.com/chromeos-dev-installer/board/daisy/full-3.168.0.0/packages/app-misc/mime-types-8.tbz2
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   127  100   127    0     0    252      0 --:--:-- --:--:-- --:--:--   305
[: 184: -ne: unexpected operator
Extracting /usr/local/portage/packages/app-misc/mime-types-8.tbz2

I think that it somehow returns a 404 everytime. Thanks for your help