'venv create' is failing with pip 10

pyperformance venv create has started failing for me recently, with the following message:

Execute: venv/cpython3.6-a7d80a339c76/bin/python -m pip install
ERROR: You must give at least one requirement to install (see "pip help install")
Command venv/cpython3.6-a7d80a339c76/bin/python -m pip install failed with exit code 1

I think this may be due to a behaviour change in pip 10.

I'm using performance v0.6.1 .

Full output below.

Creating the virtual environment venv/cpython3.6-a7d80a339c76
Execute: /home/mjw/opt/python3.6/bin/python3.6 -m venv --without-pip venv/cpython3.6-a7d80a339c76
Execute: venv/cpython3.6-a7d80a339c76/bin/python -c 'import sys; print(sys.hexversion)'
Python hexversion: 30602f0
Execute: venv/cpython3.6-a7d80a339c76/bin/python -m ensurepip --verbose
Ignoring indexes: https://pypi.python.org/simple
Collecting setuptools
  0 location(s) to search for versions of setuptools:
  Skipping link /tmp/tmpqak284a0 (from -f); not a file
  Skipping link file:///tmp/tmpqak284a0/pip-9.0.1-py2.py3-none-any.whl; wrong project name (not setuptools)
  Found link file:///tmp/tmpqak284a0/setuptools-28.8.0-py2.py3-none-any.whl, version: 28.8.0
  Local files found: /tmp/tmpqak284a0/setuptools-28.8.0-py2.py3-none-any.whl
  Using version 28.8.0 (newest of versions: 28.8.0)
Collecting pip
  0 location(s) to search for versions of pip:
  Found link file:///tmp/tmpqak284a0/pip-9.0.1-py2.py3-none-any.whl, version: 9.0.1
  Skipping link file:///tmp/tmpqak284a0/setuptools-28.8.0-py2.py3-none-any.whl; wrong project name (not pip)
  Local files found: /tmp/tmpqak284a0/pip-9.0.1-py2.py3-none-any.whl
  Using version 9.0.1 (newest of versions: 9.0.1)
Installing collected packages: setuptools, pip

  changing mode of /home/mjw/pyperf/venv/cpython3.6-a7d80a339c76/bin/easy_install-3.6 to 775

  changing mode of /home/mjw/pyperf/venv/cpython3.6-a7d80a339c76/bin/pip3 to 775
  changing mode of /home/mjw/pyperf/venv/cpython3.6-a7d80a339c76/bin/pip3.6 to 775
Successfully installed pip-9.0.1 setuptools-28.8.0
Cleaning up...
Execute: venv/cpython3.6-a7d80a339c76/bin/python -m pip --version
pip 9.0.1 from /home/mjw/pyperf/venv/cpython3.6-a7d80a339c76/lib/python3.6/site-packages (python 3.6)
Execute: venv/cpython3.6-a7d80a339c76/bin/python -m pip install -U 'setuptools>=18.5' 'pip>=6.0'
Collecting setuptools>=18.5
  Using cached https://files.pythonhosted.org/packages/20/d7/04a0b689d3035143e2ff288f4b9ee4bf6ed80585cc121c90bfd85a1a8c2e/setuptools-39.0.1-py2.py3-none-any.whl
Collecting pip>=6.0
  Using cached https://files.pythonhosted.org/packages/62/a1/0d452b6901b0157a0134fd27ba89bf95a857fbda64ba52e1ca2cf61d8412/pip-10.0.0-py2.py3-none-any.whl
Installing collected packages: setuptools, pip
  Found existing installation: setuptools 28.8.0
    Uninstalling setuptools-28.8.0:
      Successfully uninstalled setuptools-28.8.0
  Found existing installation: pip 9.0.1
    Uninstalling pip-9.0.1:
      Successfully uninstalled pip-9.0.1
Successfully installed pip-10.0.0 setuptools-39.0.1

Execute: venv/cpython3.6-a7d80a339c76/bin/python -m pip install -U wheel
Collecting wheel
  Using cached https://files.pythonhosted.org/packages/1b/d2/22cde5ea9af055f81814f9f2545f5ed8a053eb749c08d186b369959189a8/wheel-0.31.0-py2.py3-none-any.whl
Installing collected packages: wheel
Successfully installed wheel-0.31.0

Execute: venv/cpython3.6-a7d80a339c76/bin/python -m pip install
ERROR: You must give at least one requirement to install (see "pip help install")
Command venv/cpython3.6-a7d80a339c76/bin/python -m pip install failed with exit code 1

Remove directory venv/cpython3.6-a7d80a339c76