When using fill_in Capybara, the field is not filled, what's wrong?

Question

Ruby on Rails

To study integration tests, I began to use this stone.
I connected it, but when the user fills out the form, the test does not pass.

visit  new_user_path
fill_in 'Email', :with => '[email protected]'
click_button 'New user'
expect(page).to have_content 'Success'

In order to eliminate errors, only email has become a mandatory field in the model.
Then I decided to make a user form where email is filled in by default and removed fill_in

visit  new_user_path
click_button 'New user'
expect(page).to have_content 'Success'

Everything went fine, from this I concluded that the problem was with him.
Label c 'Email' exists, tried to use an identifier by id, but in vain
Then a slightly more clumsy approach (well, it seemed to me)
find('#user_email').set('[email protected]')
The test still refuses to pass.
Decided to use a launchy stone
and put it like this

visit  new_user_path
click_button 'New user'
save_and_open_page
expect(page).to have_content 'Success'

I expected to get debug information in the browser (there is my form screen), but I didn't get anything.
Perhaps not in the browser should output debugging.
I realized that fill_in does not work even before that.
What needs to be written in the Mumps config so that it fills in the fields?

Answer 1

Connect with IDs.
For example, in the case of a device:
fill_in 'user_email', :with => '[email protected]'

Answer 2

My problem was in cleaning the test database, I didn’t miss the same email) sorry