Fatal error when installing Drupal core 8.x-dev on a Mac into a folder that contains a capital letter... e.g. /Users/dan/Sites/drupal8 ...
Fatal error: Cannot redeclare standard_form_install_configure_form_alter() (previously declared in /Users/dan/Sites/drupal8/core/profiles/standard/standard.profile:12) in /Users/dan/sites/drupal8/core/profiles/standard/standard.profile on line 15
The resolution is to ensure the install.core.inc process always uses the DRUPAL_ROOT constant when calling include_once or require_once functions to ensure PHP maintains a consistent list of loaded modules. This is because PHP will resolve relative paths to a lowercase version of the full path, but DRUPAL_ROOT resolves to the correct path which may contain capital letters. Either methods are valid, but you cannot mix, as this results in a module being loaded twice.
This simply means updating the 3 lines in install.core.inc from
include_once $profile_file to
include_once DRUPAL_ROOT . '/' . $profile_file
Patch has been created (see comment #3), and now awaiting review so it can be committed.
User interface changes
No user interface changes
The only change is to refine install.core.inc file, and should not impact anything else.