Why is Xcode necessary?

[Michael Dreyfus]

I am getting ready to use the Ruby4Kids screencasts with a group of
students, so I've been testing out the setup process. One odd thing I
found is that, without installing Xcode, I was able to install the
Gosu gem and run the game I made. Is Xcode really necessary for
running the games that come out of the screencast? If not, at what
point does it become necessary?

I'm also wondering if certain parts of the install could be cut out.
Can System Tools or
UNIX Dev Support be unchecked?

[Alberto Morales]

We have experienced some issues on some systems when we did not install XCode (which installs a compiler and header files).

So when you do a gem install xxx, sometimes Ruby complains the necessary header files are not there.

I have not isolated the specific files needed, but I can't imagine anything other than a minimal install is necessary.

Alberto.

[Michael Dreyfus]

That's good news. The takeaway for me, since the kids will only need
Gosu for now, is that gosu installation will fail immediately if
there's going to be a problem. That's way better than finding out
somewhere down the road that some dependency isn't satisfied. Also,
since my systems are all identical, Xcode shouldn't be necessary on
any of them.

Here's our details for the record:

iMac with 2.26 GHz Intel Core 2 Duo
OS 10.6.8