The problem seems to be that the PHP plugin is compiled against PHP7.4 and is linked with libphp.so which points to 7.3 in bullseye and 7.4 in sid.
$ ldd /usr/lib/uwsgi/plugins/php_plugin.so | grep php libphp7.so => /usr/lib/libphp7.so (0x00007f4b8ca48000) $ ls -l /usr/lib/libphp7.so lrwxrwxrwx 1 root root 25 mai 11 19:41 /usr/lib/libphp7.so -> /etc/alternatives/libphp7 $ ls -l /etc/alternatives/libphp7 lrwxrwxrwx 1 root root 21 mai 11 19:41 /etc/alternatives/libphp7 -> /usr/lib/libphp7.4.so The php plugin should explicitly be linked against /usr/lib/libphp7.4.so
