mono

Steps:

Important thing (if using regular expressions in server names configuration in NGINX) is to make sure to pass $host as SERVER_NAME in fastcgi_params - like:
fastcgi_param SERVER_NAME $host;


Default value of $server_name will pass regexp and that will cause Mono to crash while parsing request URI.

Run cert-sync --user /etc/ssl/cert.pem. Omit --user to synchronize for entire system (note that this installs them in /usr/share/.mono rather than /usr/local/share/.mono).

Without this you might be experiencing errors like "Ssl error:1000007d:SSL routines:OPENSSL_internal:CERTIFICATE_VERIFY_FAILED" or similar

TLS 1.2 is not enabled in default version of Mono 4.8.1 port for FreeBSD.

Clone their repository from git (tarballs created by them fail way too often)

git clone https://github.com/mono/monodevelop.git

If you created and compiled unit tests using MonoDevelop you need to copy several dlls to the same directory before you can use nunit-console with compiled dll. Those libraries can be found /usr/local/lib/monodevelop/AddIns/NUnit directory

I don't have any idea if mono-tools is still supported package, but its build is badly broken at least on FreeBSD. Anyway, the only tool I find really useful there is monodoc, which luckily can be installed manually like this: