Nginx has unfortunately no really usable “rewrite log” for regex location matches. But you can create your own small (but sometimes very useful) debug output:
location ~ ^/(.*?)/(.*) {
return 200 'Debug: 1:$1 2:$2';
add_header Content-Type text/plain;
# try_files $uri /$1/index.php?$args;
}
Nginx now simply returns the generated content:
Debug: 1:xxxxx 2:yyyyy
The add_header statement is used to force text-output if you’re debugging using a web-browser (otherwise a download would be created).