What do dots after "Resolving dependencies" from bundle install (or bundle update) mean?

Question

Every time I run bundle install or bundle update, Ruby Bundler outputs something like this:

Resolving dependencies....................

The dots come out at a variable speed, sometimes tens of them in a second, sometimes stuck for a few seconds.

Just now I ran bundle update in my Jekyll blog and Bundler generated over 5,000 dots and I had to Ctrl-C it.

What do these dots mean?

Answer 1

Each gem you specify will have a list of dependent gems that it requires to run, and each of these dependencies will have a minimum and maximum compatible version.

When bundle is resolving dependencies, it's first of all ensuring the gemset you're requesting is even possible (i.e. there isn't one gem requiring ActionPack < 4 and another requiring ActionPack > 5).

After it determines whether there is a set of gems that satisfies every requirement, it starts downloading as needed. I'm guessing it picks the latest version that satisfies every relevant dependency present.