py-zipp build failure

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

I thought I read something about this having been spotted and fixed, but
I see:

===> Building for py37-zipp-0.5.1

Download error on https://pypi.org/simple/setuptools_scm/: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: un
able to get local issuer certificate (_ssl.c:1056) -- Some packages may not be found!
Download error on https://pypi.org/simple/setuptools-scm/: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: un
able to get local issuer certificate (_ssl.c:1056) -- Some packages may not be found!
Couldn't find index page for 'setuptools_scm' (maybe misspelled?)
Download error on https://pypi.org/simple/: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get loc
al issuer certificate (_ssl.c:1056) -- Some packages may not be found!
No local packages or working download links found for setuptools_scm>=1.15.0
Traceback (most recent call last):
  File "setup.py", line 6, in <module>
    setuptools.setup(use_scm_version=True)
  File "/usr/pkg/lib/python3.7/site-packages/setuptools/__init__.py", line 144, in setup
    _install_setup_requires(attrs)
  File "/usr/pkg/lib/python3.7/site-packages/setuptools/__init__.py", line 139, in _install_setup_requires
    dist.fetch_build_eggs(dist.setup_requires)
  File "/usr/pkg/lib/python3.7/site-packages/setuptools/dist.py", line 717, in fetch_build_eggs
    replace_conflicting=True,
  File "/usr/pkg/lib/python3.7/site-packages/pkg_resources/__init__.py", line 782, in resolve
    replace_conflicting=replace_conflicting
  File "/usr/pkg/lib/python3.7/site-packages/pkg_resources/__init__.py", line 1065, in best_match
    return self.obtain(req, installer)
  File "/usr/pkg/lib/python3.7/site-packages/pkg_resources/__init__.py", line 1077, in obtain
    return installer(requirement)
  File "/usr/pkg/lib/python3.7/site-packages/setuptools/dist.py", line 784, in fetch_build_egg
    return cmd.easy_install(req)
  File "/usr/pkg/lib/python3.7/site-packages/setuptools/command/easy_install.py", line 673, in easy_install
    raise DistutilsError(msg)
distutils.errors.DistutilsError: Could not find suitable distribution for Requirement.parse('setuptools_scm>=1.15.0')
*** Error code 1