More farting about with browsers. Got Links working with SSL and graphics on my Mac. To do so, install XQuartz, libpng and OpenSSL through homebrew. Then set the following flags:

set -gx LDFLAGS "-L/usr/local/opt/openssl@1.1/lib"

set -gx CPPFLAGS "-I/usr/local/opt/openssl@1.1/include"

and run

./configure --x-includes=/usr/X11/include --x-libraries=/usr/X11/lib/ --enable-graphics --with-ssl

sudo make install