Editing paragraphs field settings returns 404 with php development server

Question

I have this strange behaviour on my local drupal9 instance. I start it in the web folder with the build in php development server: php -S localhost:8000

Now if I try to edit any paragraphs field, eg. /admin/structure/paragraphs_type/manual_news/fields/paragraph.manual_news.field_news_entries

[Fri Aug 13 12:47:39 2021] 127.0.0.1:55544 [404]: POST /admin/structure/paragraphs_type/manual_news/fields/paragraph.manual_news.field_news_entries - No such file or directory

I get a 404 from the server. If it runs on a real webserver, it works.

Anybody knows how to debug / fix this?

I also opened https://www.drupal.org/project/paragraphs/issues/3228039 for this issue.

Answer 1

Clean URLs aren't supported when php -S is used to run the Drupal site because clean URLs require the .htaccess file or another file used from Nginx, which PHP doesn't use.

Either you don't use clean URLs (for example, /index.php?q=admin/structure/paragraphs_type/manual_news/fields/paragraph.manual_news.field_news_entries), or you start the server with php -S localhost:8888 .ht.router.php, where .ht.router.php is a file that comes with Drupal 9. The router script also works around a bug in PHP, reported in If the trailing path that follows a script contains a dot PATH_INFO is not set.