Creating a controller with rails generate is causing a strange error

Question

I tried to start a simple rails app today to refresh my knowledge and ran into a very strange issue...

1. Created app (rails new app-name).
2. Created controller with index action (rails g controller site index).
3. Set the root route to site#index.
4. Start rails server.

The server tries to render the index view for site, but aborts abruptly with the following error:

dyld: lazy symbol binding failed: Symbol not found: _ffi_prep_closure_loc
Referenced from: /Users/Marco/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/ffi-1.13.1/lib/ffi_c.bundle
  Expected in: /usr/lib/libffi.dylib

dyld: Symbol not found: _ffi_prep_closure_loc
  Referenced from: /Users/Marco/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/ffi-1.13.1/lib/ffi_c.bundle
  Expected in: /usr/lib/libffi.dylib

I tried (unsuccessfully):

• Upgrading my ruby version, then my rails version to latest.
• Reinstalling all my gems.
• Deleting the path to ffi_c.bundle and reinstalling ffi.

What is strange is that if I manually create the controller and the view, everything works fine!

I saw a suggestion on a somewhat related issue to try to change the C compiler on my machine to the default, but I don't understand why that would be necessary and I'd like to get a deeper understanding about what's going on.

Answer 1

I am having the same issues, and yes the file exists. I rolled my project back to ffi '~> 1.12.2' and it is working fine again.

Answer 2

It seems the issue has something to do with libffi version conflicts.

A workaround: gem inst ffi -- --disable-system-libffi

I raised an issue, see here: https://github.com/ffi/ffi/issues/791