Not sure if we should do it or not:

1. MacPorts maintainers will create a port file for Python 3.7 and they will just configure it with `configure --with-openssl=$PREFIX", where PREFIX is /opt/local by default.

2. This, however, would certainly improve the experience of manually building CPython on MacOS with macports (this would directly benefit guys like me).

The good news is that, since Christian's recent enhancements in Issue32598 to have autoconf use pkg-config to detect OpenSSL header and lib files, configure will now automatically find the MacPorts OpenSSL as long as the MacPorts bin directory (typically /opt/local/bin) is in the shell PATH when you run configure.  MacPorts supplies pkg-config and .pc files for various packages it installs including OpenSSL. (Apple doesn't ship a copy of pkg-config with macOS).  I found this out by accident; thanks, Christian!  The current status quo is also more robust in that MacPorts is not necessarily installed in /opt/local, a problem with PR 5388 as it stands.  I install MacPorts from source to a non-standard location so it would be good for someone to verify that the current 3.7 configure works with a default (/opt/local) binary install of MacPorts.

> The good news is that, since Christian's recent enhancements in Issue32598 to have autoconf use pkg-config to detect OpenSSL header and lib files, configure will now automatically find the MacPorts OpenSSL as long as the MacPorts bin directory (typically /opt/local/bin) is in the shell PATH when you run configure.

/opt/local/bin *is* in my shell's PATH and `./configure' still fails to auto-discover OpenSSL:

    ~ » echo $PATH
    /Users/yury/dev/bin /opt/local/bin /opt/local/sbin /usr/local/bin /usr/bin /bin /usr/sbin /sbin /usr/local/share/dotnet /Users/yury/dev/sys-venvs/fish/bin

OK, so the trick is to first install pkg-config:

   sudo port install pkgconfig
   ./configure
   make
   python -m ssl  # works

I'll close the PR then, but we need to document this trick with pkg-config somewhere.

Good!  Yes, that should go into the devguide.  Unfortunately, it only works with 3.7+, so the CFLAGS/LDFLAGS stuff is still needed for 3.6- and 2.7.

Hmm, I spoke a bit too soon. I now see one side effect of Christian's change is to break the suggested code in the devguide for using a local or private version of OpenSSL on macOS at least, e.g. supplying the paths via CPPFLAGS and LDFLAGS.  If there is a pkg-config available on the path that supplies the same values, the net effect is the same but having pkg-config available wasn't a requirement previously and should not now be.  We'll probably need to fix this in a more general way than PR 5388 proposed.  I'll try to take a look at it before beta 1 freeze but, if not, it should be fixed for beta 2.

Can we also cover Brew?

Here's the dumb little configure wrapper I use:

```
#!/bin/sh

export CPPFLAGS="-I$(brew --prefix sqlite3)/include -I$(brew --prefix zlib)/include"
export LDFLAGS="-L$(brew --prefix sqlite3)/lib -L$(brew --prefix zlib)/lib"
export PKG_CONFIG_PATH="/usr/local/opt/openssl/lib/pkgconfig"

./configure
```

At the PyCon US sprints, we looked into this and updated the Developer's Guide with suggestions for how to configure a build on macOS with either Homebrew or MacPorts for either 3.7+ or earlier.  It is not an ideal solution so I want to keep this open for now and reassign to me but it should no longer be a "deferred blocker".

For reference, the devguide now recomments this:

(Homebrew)

$ brew install openssl xz
and configure python versions >= 3.7:

./configure --with-pydebug --with-openssl=$(brew --prefix openssl)
or configure python versions < 3.7:

$ CPPFLAGS="-I$(brew --prefix openssl)/include" \
  LDFLAGS="-L$(brew --prefix openssl)/lib" \
  ./configure --with-pydebug

(MacPorts)

$ sudo port install pkgconfig openssl xz
and configure:

$ CPPFLAGS="-I/opt/local/include" \
  LDFLAGS="-L/opt/local/lib" \
  ./configure --with-pydebug