NC 22 upgrade stuck + "Could not open input file: occ"

Nextcloud version (eg, 20.0.5): 22.2.0
Operating system and version (eg, Ubuntu 20.04): Devuan Chimaera 4.0, Docker v. 20.10

The issue you are facing:

I’m running Nextcloud in a Linuxserver.io Docker container. The container is fully updated, as is the mariadb container that holds the data.

Updating from minor version 22.2.0 (I think) to 22.2.2. The GUI updater has been stuck at step 4 (Downloading), for over 12 hours.

This has happened once or twice before. In the past I would enter the Docker container (docker exec -it nextcloud /bin/bash) and run the following:

sudo -u abc -s /bin/bash -c "php7 /config/www/nextcloud/occ upgrade" 

and then continue to take the Nextcloud instance out of maintenance mode when things are done. This time, however, I get the following response:

Could not open input file: /config/www/nextcloud/occ

I’ve tried to run the above command with “/usr/bin/occ” instead (since that’s where occ seems to be located), but get the feedback

sudo -u abc -s /bin/bash -c "php7 /config/www/nextcloud/occ $*"

so it looks like I did it the “proper way” the first time. No matter what I’ve tried that invokes occ I get the same response. I’m stumped, I have no idea where to go from here. Any help that I’ve been able to find on stuck updates always assumes that occ will just run.

Inside the container /config/log/php/error.log has nothing of value, but /config/log/nginx/ has

2021/11/12 17:14:10 [error] 415#415: *187 upstream timed out (110: Operation timed out) while reading response header from upstream, client: 75.161.40.229, server: _, request: "POST /updater/index.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "nextcloud.mydomain.org"
2021/11/12 17:24:43 [error] 415#415: *223 upstream timed out (110: Operation timed out) while reading response header from upstream, client: 75.161.40.229, server: _, request: "POST /updater/index.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "nextcloud.mydomain.org"
2021/11/12 17:59:43 [error] 415#415: *349 FastCGI sent in stderr: "PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/resources/config/mimetypemapping.dist.json): failed to open stream: No such file or directory in /config/www/nextcloud/updater/index.php on line 1048PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/resources/config/mimetypemapping.dist.json,/config/www/nextcloud/updater/../resources/config/mimetypemapping.dist.json): No such file or directory in /config/www/nextcloud/updater/index.php on line 1048" while reading response header from upstream, client: 75.161.40.229, server: _, request: "POST /updater/index.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "nextcloud.mydomain.org"
2021/11/12 22:05:44 [error] 415#415: *865 FastCGI sent in stderr: "PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/resources/codesigning/root.crt): failed to open stream: No such file or directory in /config/www/nextcloud/updater/index.php on line 1048PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/resources/codesigning/root.crt,/config/www/nextcloud/updater/../resources/codesigning/root.crt): No such file or directory in /config/www/nextcloud/updater/index.php on line 1048" while reading response header from upstream, client: 75.161.40.229, server: _, request: "POST /updater/index.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "nextcloud.mydomain.org"
2021/11/12 22:06:02 [error] 415#415: *867 FastCGI sent in stderr: "PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/resources/update-locales.php): failed to open stream: No such file or directory in /config/www/nextcloud/updater/index.php on line 1048PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/resources/update-locales.php,/config/www/nextcloud/updater/../resources/update-locales.php): No such file or directory in /config/www/nextcloud/updater/index.php on line 1048" while reading response header from upstream, client: 75.161.40.229, server: _, request: "POST /updater/index.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "nextcloud.mydomain.org"
2021/11/12 22:06:08 [error] 415#415: *869 FastCGI sent in stderr: "PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/config/config.sample.php): failed to open stream: No such file or directory in /config/www/nextcloud/updater/index.php on line 1048PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/config/config.sample.php,/config/www/nextcloud/updater/../config/config.sample.php): No such file or directory in /config/www/nextcloud/updater/index.php on line 1048" while reading response header from upstream, client: 75.161.40.229, server: _, request: "POST /updater/index.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "nextcloud.mydomain.org"
2021/11/12 22:06:09 [error] 415#415: *871 FastCGI sent in stderr: "PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/3rdparty/mtdowling/jmespath.php/src/FnDispatcher.php): failed to open stream: No such file or directory in /config/www/nextcloud/updater/index.php on line 1048PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/3rdparty/mtdowling/jmespath.php/src/FnDispatcher.php,/config/www/nextcloud/updater/../3rdparty/mtdowling/jmespath.php/src/FnDispatcher.php): No such file or directory in /config/www/nextcloud/updater/index.php on line 1048" while reading response header from upstream, client: 75.161.40.229, server: _, request: "POST /updater/index.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "nextcloud.mydomain.org"
2021/11/12 22:06:12 [error] 415#415: *873 FastCGI sent in stderr: "PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/3rdparty/mtdowling/jmespath.php/LICENSE): failed to open stream: No such file or directory in /config/www/nextcloud/updater/index.php on line 1048PHP message: PHP Warning:  rename(/data/updater-ocu2j8balume/downloads/nextcloud/3rdparty/mtdowling/jmespath.php/LICENSE,/config/www/nextcloud/updater/../3rdparty/mtdowling/jmespath.php/LICENSE): No such file or directory in /config/www/nextcloud/updater/index.php on line 1048" while reading response header from upstream, client: 75.161.40.229, server: _, request: "POST /updater/index.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "nextcloud.mydomain.org"
2021/11/12 22:07:37 [error] 415#415: *883 upstream timed out (110: Operation timed out) while reading response header from upstream, client: 75.161.40.229, server: _, request: "POST /updater/index.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "nextcloud.mydomain.org"

Any ideas on how to fix this?

Anyone? Bueller?