pin-project | A crate for safe and ergonomic pin-projection

I have no experience with installing this myself but may be able to give some pointers.

First of all about your effort to install OpenSSL. After cloning the repository, you do not select any particular branch before configuring and making. This means that you are building the master branch, which is an evolving version of OpenSSL 3.0.0. This is not a supported version according to the crate's documentation. In order to build a supported version of OpenSSL, you will have to switch to some 1.1.1 branch or tag. Alternatively, you can download the 1.1.1 version from OpenSSL's download page.

That said, it does not seem necessary to install OpenSSL from source. Under the section Automatic, the documentation explains that the crate can deal with all kinds of typical OpenSSL installations. It may be easier for you to follow that, if possible in your case. If so, then you should unset the OPENSSL_DIR environment variable otherwise that will (continue to) override the crate's automatic mechanisms to find the OpenSSL installation.

If you still want to stick with the Manual configuration, then indeed you should use environment variables, and OPENSSL_DIR seems a convenient one. However, it does not mean the same thing as the openssldir parameter that you used in your configure command ./config --openssldir=/usr/local/ssl. To get the details, check out the meaning of that configuration parameter. In fact, the crate's meaning of OPENSSL_DIR corresponds to the --prefix setting (which you did not configure).

The problem you are running into now is that your OPENSSL_DIR variable points to your directory for OpenSSL configuration files, whereas the crate expects it to point to the top of the actual OpenSSL installation directory tree (which in your case seems to reside at /usr/local).