install.sh: PATH= with no $PATH inside

[Jaspur]

The https://raw.github.com/robbyrussell/oh-my-zsh/master/tools/install.sh file gives an error:

Cloning Oh My Zsh...
Cloning into '/home/vagrant/.oh-my-zsh'...
Looking for an existing zsh config...
Using the Oh My Zsh template file and adding it to ~/.zshrc
Copying your current PATH and adding it to the end of ~/.zshrc for you.
Time to change your default shell to zsh!
Password: chsh: PAM authentication failed
         __                                     __
  ____  / /_     ____ ___  __  __   ____  _____/ /_
 / __ \/ __ \   / __ `__ \/ / / /  /_  / / ___/ __ \

  * WARNING: Above files contains `PATH=` with no `$PATH` inside, this can break RVM,
    for details check https://github.com/wayneeseguin/rvm/issues/1351#issuecomment-10939525
    to avoid this warning append #PATH.

No binary rubies available for: ubuntu/12.04/x86_64/ruby-2.1.1.
Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 11.4M  100 11.4M    0     0  3841k      0  0:00:03  0:00:03 --:--:-- 6780k
/home/vagrant/.oh-my-zsh/oh-my-zsh.sh: line 13: syntax error near unexpected token `('
/home/vagrant/.oh-my-zsh/oh-my-zsh.sh: line 13: `for config_file ($ZSH/lib/*.zsh); do'
ERROR:  While executing gem ... (Gem::FilePermissionError)
    You don't have write permissions into the /opt/vagrant_ruby/lib/ruby/gems/1.8 directory.

It refers to rvm/rvm#1351 (comment) , but from what I can see that is already done at line 30 of install.sh

[avit]

This is a follow-up to #1359. I think we should reconsider it.

The problem is when we copy over the user's existing PATH we have no way to know what parts they customized for themselves in their previous ~.bashrc and what parts came from elsewhere on the system.

Options:

1. We could prepend PATH="\$PATH:..." on the front anyway: it would create some duplicate entries in the list and the user's original precedence would be moved to the end.
2. We could read other existing ~/.*rc and ~/.profile files for PATH= entries and insert those instead of the expanded literal $PATH.

[avit]

See possible solution in #2589.

[foffer]

I'm also stuck on this. Is there any simple solution to the problem?