Reset rubygems’ internal cache of known gems after maniuplating $LOAD_PATH

When you require something via rubygems for the first time, it creates a list of “all known gem specficiations”, meaning .gemspec files.

If you add something to the $LOAD_PATH that has more gems in it (in my case, this was a jar, because I’m in jruby at the moment), the new .gemspec files are in the new path are not known by rubygems, and it has the “all” set cached. You can see the cache with:

Gem::Specification.class_variable_get(:@@all)

Here’s how you can reset it after adding to the $LOAD_PATH:

Gem::Specification.reset

This took me a few hours to figure out, so maybe this post will help someone.

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