Overriding default hashing mechanism: cannot redeclare user_hash_password() I have a project that requires a change in the default password encryption mechanism.

The documentation of password.inc states that this can be overridden using the password_inc variable. I followed the instructions as stated in the documentation but when trying to change a password on the website following error is generated:


  Cannot redeclare user_hash_password() (previously declared in
  /.../drupal7/includes/password.inc:207) in
  /.../drupal7/sites/foo/modules/custom/foo_custom/includes/foo_custom.password.inc
  ...


I have searched the code for a hardcoded include on includes/password.inc but can't find anything.

Any ideas?
Everything in core uses 

require_once DRUPAL_ROOT . '/' . variable_get('password_inc', 'includes/password.inc');


so I would guess at the cause being a contrib module. 

Also just check that the password_inc variable has been updated correctly and not deleted somehow.