Supporting every version of the software that we depend on is not feasible, so we support a limited, “modern-ish” system configuration.
We follow the list of currently supported PHP versions provided by the community. Unsupported/EOL versions of PHP will not be supported under any circumstances.
Composer 2.2 (LTS) is the minimum version. However, few people run such an old version of Composer and we do not regularly test functionality with anything other than the current stable release. If you run into problems, we will ask you to try a recent version of Composer before proceeding with troubleshooting.
The core plugin used to use multiple tools to try to apply a patch. Unfortunately, that led to a lot of unpredictable behavior across various environments. Now, the core plugin only relies on Git. As long as you have a relatively recent version of Git, things should work.
If your Git is older than what is distributed with the current Debian “stable” release, we probably won’t be able to do much with it.