'rails generate' commands hang when trying to create a model

Found this over at http://www.dixis.com/?p=754

For one of my projects I am using rails 4.1 (bleeding edge! yeah :) ) and suddenly noticed, that after opening my laptop in the morning my normal rails commands, like

$> rails c
$> rails g migration Bla name description some_more_fields

just … were hanging and nothing happened??? Like they were waiting for further input. Upon closer investigation, I assumed that the connection to the spring process was lost/corrupt (I move between networks a lot? maybe that could explain it).

For those unaware, as I was, spring is a Rails application preloader. It speeds up development by keeping your application running in the background so you don’t need to boot it every time you run a test, rake task or migration. Of course when that connection is lost, or corrupt, it hangs.

A simple

$> spring stop

stops the spring server, after which any rails command will restart it automatically. Fixed :)

If your rails generate commands hangs, it is most likely that the generated binstubs of rails are the issue. As you mentioned, you renamed the project.

My educated guess is that some paths in the binstubs were still set to the old project directory but did not exist any longer.

There is a great article on how binstubs work here: https://github.com/sstephenson/rbenv/wiki/Understanding-binstubs

rails 4

To reset the binstubs, just delete your bin/ directory in rails and run:

# generates binstubs for ALL gems in the bundle
bundle install --binstubs

# ...OR, generate binstubs for a SINGLE gem (recommended)
bundle binstubs rake

rails 5/rails 6

To reset the binstubs, just delete your bin/ directory in rails and run:

rake app:update:bin

Why do we need to use the 'rake' command for rails 5 and higher, and not the 'rails' command itself?

Since rails 5 some 'rake' commands are encapsulated within the 'rails' command. However when one deletes 'bin/' directory one is also removeing the 'rails' command itself, thus one needs to go back to 'rake' for the reset since 'rails' is not available any longer but 'rake' still is.