Pow 0.5.0 install error on El Capitan

Question

I've been trying to install Pow 0.5.0 on my fresh installation of El Capitan. I'm using their direct install script. I get the following error:

~ $ sudo curl get.pow.cx | sh
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  9039  100  9039    0     0   5970      0  0:00:01  0:00:01 --:--:--  5970

*** Installing Pow 0.5.0...
*** Installing local configuration files...

/Users/siddhartharun/Library/Application Support/Pow/Versions/0.5.0/lib/command.js:78

throw err;
file exists

Here are the troubleshooting steps I've tried:

1. Attempted to reinstall pow with sudo curl get.pow.cx | sh
2. Removed existing /etc/resolver directory then reinstalled
3. removed both ~/.pow and ~/.powconfig then reinstalled
4. manually run sudo rm -rf ~/Library/Application Support/Pow then reinstall

But I've had no luck. I don't want to use DNSMASQ to setup .dev domains because I find Anvil + Pow to be a much better solution. Can anybody help?