Installing certbot +python37 results in many py27-* modules getting installed and a build failure

[jeremyhu (Jeremy Huddleston Sequoia)]

With base master (bc008721189ff719dc1ac70a06a476ff6013c63b), dependencies for python projects seems incorrect.

I'm trying to install certbot +python37. It's pulling in dependencies on python 2.7 modules:

(15:50:37 Tue Apr 23 2019 jeremy@cid x86_64)
~/src/macports/dports/security/certbot (master) $ sudo port -v -s upgrade
--->  Computing dependencies for py27-setuptools.
--->  Fetching distfiles for py27-setuptools
--->  Verifying checksums for py27-setuptools
--->  Checksumming setuptools-41.0.0.zip
--->  Extracting py27-setuptools
--->  Extracting setuptools-41.0.0.zip
...
--->  Configuring py27-setuptools
--->  Building py27-setuptools
...
--->  Staging py27-setuptools into destroot
...
--->  Installing py27-setuptools @41.0.0_0
...
--->  Activating py27-setuptools @41.0.0_0
...
--->  Cleaning py27-setuptools
--->  Removing work directory for py27-setuptools
--->  Computing dependencies for certbot.
--->  Building certbot
Executing:  cd "/opt/local/var/macports/build/_Users_jeremy_src_macports_macports-ports_security_certbot/certbot/work/certbot-0.33.1" && /opt/local/Library/Frameworks/Python.framework/Versions/3.7/bin/python3.7 setup.py --no-user-cfg build 
Traceback (most recent call last):
  File "setup.py", line 6, in <module>
    from setuptools import find_packages, setup
ModuleNotFoundError: No module named 'setuptools'
Command failed:  cd "/opt/local/var/macports/build/_Users_jeremy_src_macports_macports-ports_security_certbot/certbot/work/certbot-0.33.1" && /opt/local/Library/Frameworks/Python.framework/Versions/3.7/bin/python3.7 setup.py --no-user-cfg build 
Exit code: 1
Error: Failed to build certbot: command execution failed
Error: See /opt/local/var/macports/logs/_Users_jeremy_src_macports_macports-ports_security_certbot/certbot/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets to report a bug.

[jeremyhu (Jeremy Huddleston Sequoia)]

main.log

[jmroot (Joshua Root)]

The dependencies are specified using ${python.version} before that is set by the variants.

[jmroot (Joshua Root)]

In e91b3d591ae213e4b350dafcee0295d720918ad2/macports-ports (master):

certbot: fix dependencies

Fixes: #58377