Hello,
>
> That's a reasonable assumption, though. It's kind of like saying "Perhaps the 
> program should check if the home directory actually exists..."
>   

Is it not good programming practice to check if resource exists before
using?

> It might be nice to have a user-friendly option about this, 

IMHO, it would be user-friendly if software emits error when required
resource not available (and make program barf).

> but really, if tmp 
> doesn't exist, you're going to have a lot more problems than that one 
> installer.
>   
(Score:5, Insightful)   :)

And very much my experience.

This is my first week using Ruby, so please tolerate a newbie question:

Is it general convention/assumption by all Ruby programmers: a Ruby
program always has valid writable Dir.tmpdir defined, without verification?

Cheers,
az