> This is a rather basic question- but for a standard compile of the ruby
> binary what external "dependencies" does it have? Is there some sort of
> associated gems directory?

As background, for 1.9.3-p0 from the RubyInstaller project we provide the
following dependencies for Windows users:

  * libyaml
  * libffi
  * openssl
  * libgdbm
  * libiconv
  * libz
  * pdcurses
  * tcl/tk
  * rb-readline (pure Ruby readline)

But depending up how you're using MRI, not all of these are currently
required.

In fact, you can successfully build a minimal MRI with none of those
dependencies. The current build process will try to configure core
extensions (fiddle, psych, tk, etc) to use the dependencies but will _not_
fail the build if those dependencies aren't found.

For example, even though you may not have `libyaml`, the build will try to
configure `psych`, warn that it can't, and complete. When you run the built
MRI, you'll most likely get a runtime warning saying you need to install
`libyaml`. However, you can (currently) still process YAML using the
unmaintained (IIRC) built-in `syck` library that was built as part of the
minimal build. I'm not sure how much longer this will continue to be true.

To answer your question, try a minimal build using something like the
following and watch the build messages as the process tries to configure
and build extensions:

  ./configure --enable-shared --disable-install-doc && make

Jon

---
http://thecodeshop.github.com | http://jonforums.github.com/
twitter: @jonforums