Don't bother uninstalling. It'll just come back in updates.mapple leaves /us=
r/local completely alone, so edit /etc/paths to have /usr/local/bin first. T=
hen, install Xcode via the AppStore so you can compile ruby and gems with c e=
xtensions. Then install Mac homebrew and use that to install ruby 1.9. Rvm i=
s nice in certain contexts but really isn't necessary and overly complicates=
 things.

On Sep 14, 2012, at 11:11, sto.mar / web.de wrote:

> Hi all,
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> I am using Ruby in an introductory computer science class in Highschool.
> Of course, to keep things simple, I would like all my students to use
> the same Ruby version (1.9.3p194).
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> At school we use W*****s machines and most of the students also use it
> at home, but a few use Linux or OS X. Myself, I'm a convinced Linux user
> so I do want to encourage my students to use a non-W*****s operating
> system.
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> Problem is I have never used OS X and need some help from you
> experienced users out there:
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> it seems that by default Ruby is already installed on OS X, but in
> the wrong (for our purposes) version, 1.8.7. I think the student
> who pointed that out to me uses Mountain Lion (maybe Lion).
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> What would be the least painful option, in your opinion:
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> - somehow uninstall the preinstalled version and install 1.9.3
>  (I fear this could break the system, assuming Ruby is
>   needed for some system tool(?) since it's already installed)
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> - install rvm
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> - ...?
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> - tolerate that students use different versions
>  (this might mean higher effort for me when providing
>   unit tests for programming tasks etc.)
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> Any hint is highly appreciated.
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> --=20
> <https://github.com/stomar/>
>=20