Uname -a:

FreeBSD lilith 11.2-RELEASE-p4 FreeBSD 11.2-RELEASE-p4 #0 r339065: Mon Oct  1 14:01:40 EDT 2018     root@lilith:/usr/obj/usr/src/sys/GENERIC  amd64

Portmaster output:

===>>> Launching child to install devel/py-setuptools_scm@py27

===>>> All >> devel/py-setuptools_scm@py27 (6/6)

===>>> Currently installed version: py27-setuptools_scm-1.17.0
===>>> Port directory: /usr/ports/devel/py-setuptools_scm@py27

===>>> Starting check for build dependencies
===>>> Gathering dependency list for devel/py-setuptools_scm@py27 from ports
===>>> Dependency check complete for devel/py-setuptools_scm@py27

===>>> All >> py27-setuptools_scm-1.17.0 (6/6)

===>  Cleaning for py27-setuptools_scm-3.1.0
/!\ WARNING /!\

You have security/libressl installed but do not have
DEFAULT_VERSIONS+=ssl=libressl set in your make.conf

===>  License MIT accepted by the user
===>   py27-setuptools_scm-3.1.0 depends on file: /usr/local/sbin/pkg - found
===> Fetching all distfiles required by py27-setuptools_scm-3.1.0 for building
===>  Extracting for py27-setuptools_scm-3.1.0
=> SHA256 Checksum OK for setuptools_scm-3.1.0.tar.gz.
===>  Patching for py27-setuptools_scm-3.1.0
===>   py27-setuptools_scm-3.1.0 depends on package: py27-setuptools>0 - found
===>   py27-setuptools_scm-3.1.0 depends on file: /usr/local/bin/python2.7 - found
===>  Configuring for py27-setuptools_scm-3.1.0
running config
===>  Building for py27-setuptools_scm-3.1.0
running build
running build_py
creating build
creating build/lib
creating build/lib/setuptools_scm
copying src/setuptools_scm/discover.py -> build/lib/setuptools_scm
copying src/setuptools_scm/git.py -> build/lib/setuptools_scm
copying src/setuptools_scm/utils.py -> build/lib/setuptools_scm
copying src/setuptools_scm/__main__.py -> build/lib/setuptools_scm
copying src/setuptools_scm/file_finder_git.py -> build/lib/setuptools_scm
copying src/setuptools_scm/file_finder.py -> build/lib/setuptools_scm
copying src/setuptools_scm/hacks.py -> build/lib/setuptools_scm
copying src/setuptools_scm/hg.py -> build/lib/setuptools_scm
copying src/setuptools_scm/win_py31_compat.py -> build/lib/setuptools_scm
copying src/setuptools_scm/integration.py -> build/lib/setuptools_scm
copying src/setuptools_scm/__init__.py -> build/lib/setuptools_scm
copying src/setuptools_scm/version.py -> build/lib/setuptools_scm
copying src/setuptools_scm/file_finder_hg.py -> build/lib/setuptools_scm
copying src/setuptools_scm/config.py -> build/lib/setuptools_scm
===>>> Building the port required 11 seconds
===>  Staging for py27-setuptools_scm-3.1.0
===>   Generating temporary packing list
running install
running build
running build_py
running install_lib
creating /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7
creating /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages
creating /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/hg.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/__main__.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/git.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/version.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/integration.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/hacks.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/discover.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/utils.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/__init__.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/file_finder_git.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/config.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/file_finder.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/file_finder_hg.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
copying build/lib/setuptools_scm/win_py31_compat.py -> /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/hg.py to hg.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/__main__.py to __main__.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/git.py to git.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/version.py to version.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/integration.py to integration.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/hacks.py to hacks.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/discover.py to discover.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/utils.py to utils.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/__init__.py to __init__.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/file_finder_git.py to file_finder_git.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/config.py to config.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/file_finder.py to file_finder.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/file_finder_hg.py to file_finder_hg.pyc
byte-compiling /usr/ports/devel/py-setuptools_scm/work-py27/stage/usr/local/lib/python2.7/site-packages/setuptools_scm/win_py31_compat.py to win_py31_compat.pyc
writing byte-compilation script '/tmp/tmpqAbg7k.py'
/usr/local/bin/python2.7 -O /tmp/tmpqAbg7k.py
removing /tmp/tmpqAbg7k.py
running install_egg_info
running egg_info
writing src/setuptools_scm.egg-info/PKG-INFO
writing top-level names to src/setuptools_scm.egg-info/top_level.txt
writing dependency_links to src/setuptools_scm.egg-info/dependency_links.txt
writing entry points to src/setuptools_scm.egg-info/entry_points.txt
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "setup.py", line 116, in <module>
    setuptools.setup(**arguments)
  File "/usr/local/lib/python2.7/site-packages/setuptools/__init__.py", line 143, in setup
    return distutils.core.setup(**attrs)
  File "/usr/local/lib/python2.7/distutils/core.py", line 151, in setup
    dist.run_commands()
  File "/usr/local/lib/python2.7/distutils/dist.py", line 953, in run_commands
    self.run_command(cmd)
  File "/usr/local/lib/python2.7/distutils/dist.py", line 972, in run_command
    cmd_obj.run()
  File "/usr/local/lib/python2.7/site-packages/setuptools/command/install.py", line 61, in run
    return orig.install.run(self)
  File "/usr/local/lib/python2.7/distutils/command/install.py", line 575, in run
    self.run_command(cmd_name)
  File "/usr/local/lib/python2.7/distutils/cmd.py", line 326, in run_command
    self.distribution.run_command(command)
  File "/usr/local/lib/python2.7/distutils/dist.py", line 972, in run_command
    cmd_obj.run()
  File "/usr/local/lib/python2.7/site-packages/setuptools/command/install_egg_info.py", line 34, in run
    self.run_command('egg_info')
  File "/usr/local/lib/python2.7/distutils/cmd.py", line 326, in run_command
    self.distribution.run_command(command)
  File "/usr/local/lib/python2.7/distutils/dist.py", line 972, in run_command
    cmd_obj.run()
  File "/usr/local/lib/python2.7/site-packages/setuptools/command/egg_info.py", line 296, in run
    self.find_sources()
  File "/usr/local/lib/python2.7/site-packages/setuptools/command/egg_info.py", line 303, in find_sources
    mm.run()
  File "/usr/local/lib/python2.7/site-packages/setuptools/command/egg_info.py", line 534, in run
    self.add_defaults()
  File "/usr/local/lib/python2.7/site-packages/setuptools/command/egg_info.py", line 573, in add_defaults
    rcfiles = list(walk_revctrl())
  File "/usr/local/lib/python2.7/site-packages/setuptools/command/sdist.py", line 20, in walk_revctrl
    for item in ep.load()(dirname):
  File "/usr/ports/devel/py-setuptools_scm/work-py27/setuptools_scm-3.1.0/src/setuptools_scm/integration.py", line 28, in find_files
    command = ep.load()
  File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2346, in load
    return self.resolve()
  File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2356, in resolve
    raise ImportError(str(exc))
ImportError: 'module' object has no attribute 'FILES_COMMAND'
*** Error code 1

Stop.
make: stopped in /usr/ports/devel/py-setuptools_scm

===>>> make stage failed for devel/py-setuptools_scm@py27
===>>> Aborting update

===>>> Update for devel/py-setuptools_scm@py27 failed
===>>> Aborting update