Question: I'm trying to create a UITableViewCell which contains 3 subviews - a button, and two labels. The table view cell should look like this:

```
Button --Label 1-----------
       --Label 1 continued--

  --Label 2-----------------
  --Label 2 continued ------

```

Currently, I have button one, with leading, top, width, and height constraints pinning it to the top left. Label 1 has a leading constraint from the Button, top, left and bottom constraints to the content view. Label 1 has number of lines set to 0 and can dynamically expand, and this works so far.

I'm having trouble figuring out how to set constraints for Label 2 so that it is always below Label 1 and can also expand. 

I've tried setting a top constraint on Label 2 to the bottom of Label 1, with all other sides pinned to the content view, but this gave the error that height and vertical position were ambiguous. What constraints do I need to add for Label 2?

Answer: 
`bundle exec` just ensures that all gems in Gemfile are installed (globally or on userspace or in `vendor/bundle` directory of the project) when running the command. It's explained in more detail in <https://bundler.io/man/bundle-exec.1.html> (especifically <https://bundler.io/man/bundle-exec.1.html#BUNDLE-INSTALL-BINSTUBS> section):

> 
> ### Bundle Install --binstubs
> 
> 
> If you use the `--binstubs` flag in `bundle install`, Bundler will automatically create a directory (which defaults to `app_root/bin`) containing all of the executables available from gems in the bundle.
> 
> 
> After using `--binstubs`, `bin/rspec spec/my_spec.rb` is identical to
> `bundle exec rspec spec/my_spec.rb`.
> 
> 
> 

Binstubs may also include other customizations like loading `spring` gem, which preloads and speeds up the Rails application.
Bundle exec is a Bundler command.

You should use bundle exec in all the cases as it

> 
> bundle-exec - Execute a command in the context of the bundle
> 
> 
> 

More info can be found here: <http://bundler.io/v1.15/bundle_exec.html>

bin/rails might work but only if all the required gems/executables are present on your system without the scope of the bundle. 

In short if you have all the gems installed on your system (eg. globally) the bin/rails will work (but might generate conflicts). If you however installed them only within the scope of the bundle they might not work. 

`bundle exec` ensures that the gems and their versions from your Gemfile are being used.