I am still trying to figure this out. Looks like the exact same problem as this: 502 Bad Gateway (nginx/1.16.0) in all sites after update
The OP of this topic is also running MacOS Mojave (10.14.6), just like I do. Upgrading the mac os is not really an option, since it runs older software.
I looked into the logfile that is written to the logs folder in Local.
When I start the site it writes:
[18-Nov-2022 15:01:05] NOTICE: fpm is running, pid 2449
[18-Nov-2022 15:01:05] NOTICE: ready to handle connections
When I acces the site nothing is written to the logfile.
Then, when trying to acces wp-admin it writes:
[18-Nov-2022 15:01:21] WARNING: [pool www] child 2458 said into stderr: "dyld: lazy symbol binding failed: Symbol not found: ___darwin_check_fd_set_overflow"
[18-Nov-2022 15:01:21] WARNING: [pool www] child 2458 said into stderr: " Referenced from: /Users/bobeager/Library/Application Support/Local/lightning-services/php-8.0.22+3/bin/darwin/sbin/../dylibs/libcurl.4.dylib (which was built for Mac OS X 11.0)"
[18-Nov-2022 15:01:21] WARNING: [pool www] child 2458 said into stderr: " Expected in: /usr/lib/libSystem.B.dylib"
[18-Nov-2022 15:01:21] WARNING: [pool www] child 2458 said into stderr: "dyld: Symbol not found: ___darwin_check_fd_set_overflow"
[18-Nov-2022 15:01:21] WARNING: [pool www] child 2458 said into stderr: " Referenced from: /Users/bobeager/Library/Application Support/Local/lightning-services/php-8.0.22+3/bin/darwin/sbin/../dylibs/libcurl.4.dylib (which was built for Mac OS X 11.0)"
[18-Nov-2022 15:01:21] WARNING: [pool www] child 2458 said into stderr: " Expected in: /usr/lib/libSystem.B.dylib"
[18-Nov-2022 15:01:21] WARNING: [pool www] child 2458 exited on signal 6 (SIGABRT) after 16.487523 seconds from start
[18-Nov-2022 15:01:21] NOTICE: [pool www] child 2471 started
Not sure what to make of this, perhaps it could give others a direction what is causing the error?