[Rails] Re: There is a difference between "rake" and "bundle exec rake" and I need to understand it.
Tuesday, January 6, 2015
On Tuesday, January 6, 2015 4:52:34 PM UTC, Chris Miller wrote:
Hi Folks,I think I need to understand this fundamental architectural question. I don't know if it is a Ruby question or a Rails question, or a Ruby on Rails question.Clearly I have multiple versions. Clearly I am supposed to have multiple versions. Clearly there is an accommodation for multiple versions. Clearly I don't understand how this accommodation works.Apparently, there are the "system" gems, and there are "bundle" gems, which are apparently controlled by my application. Presumable my application is always going to want to run in the context of the assembled gems collected for the purposes of the application. So, my first question is, how is this accomplished? Simple path search order?
bundler makes sure only the gems (and the specific versions) listed in Gemfile.lock are loaded which avoids all sorts of dependency based problems. However if you just run `rake`, then the most recent version of rake is run. A few milliseconds boot.rb loads bundler, and if bundler finds that gems have been loaded that don't match the version bundler wants to use then it aborts (since one a gem has been loaded you can't unload it and load a different version)
When you run something with bundle exec, it ensures that only the gem versions in your Gemfile.lock are specified.
You can use http://mpapis.github.io/rubygems-bundler/ which ensures that the executables installed for rake etc. load bundler first. You can also use the bin stubs in your app's bin folder .
I seem to recall the passenger knows to load bundler if a Gemfile is present - i don't recall ever having to do something specific for this.
Fred
For whatever reason, different versions are being selected in different contexts. I don't know enough about how Ruby or Rails does things to understand this, but I have a simple example:$ rake time:zones:localrake aborted!You have already activated rake 10.0.4, but your Gemfile requires rake 10.3.2. Prepending `bundle exec` to your command may solve this./var/www/vhost/todo.tryx.org/tracks/config/boot.rb:6:in `<top (required)>'/var/www/vhost/todo.tryx.org/tracks/config/application.rb: `<top (required)>'1:in /var/www/vhost/todo.tryx.org/tracks/Rakefile:5:in `<top (required)>'(See full trace by running task with --trace)$ bundle exec rake time:zones:local* UTC -08:00 *Pacific Time (US & Canada)TijuanaIsn't there some way to declare that the bundle context should be the default? In my case, I am running the Ruby on Rails application through Passenger, so I need to declare, "Use the bundle context" as the default. If somebody could point me in the direction of a manual that explains why all this works the way it does, I'd be appreciative.Thanks for the help,Chris.
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