Build failure

[tdruez]

In GitHub action and RTD:
Since f74a3bb

Look like regipy is the culprit, starting an infinite packages collection:

Collecting inflection==0.5.1
  Downloading inflection-0.5.1-py2.py3-none-any.whl (9.5 kB)
Collecting regipy>=2.0.0
  Downloading regipy-2.1.0.tar.gz (37 kB)
  Downloading regipy-2.0.2.tar.gz (33 kB)
  Downloading regipy-2.0.1.tar.gz (33 kB)
  Downloading regipy-2.0.0.tar.gz (32 kB)
INFO: pip is looking at multiple versions of regex to determine which version is compatible with other requirements. This could take a while.
Collecting regex>=2020.1.8
  Downloading regex-2021.9.30-cp37-cp37m-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (747 kB)
  Downloading regex-2021.9.24-cp37-cp37m-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (747 kB)
  Downloading regex-2021.8.28-cp37-cp37m-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (745 kB)
  Downloading regex-2021.8.21-cp37-cp37m-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (747 kB)
  Downloading regex-2021.8.3-cp37-cp37m-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (722 kB)
  Downloading regex-2021.7.6-cp37-cp37m-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (722 kB)
  Downloading regex-2021.7.5-cp37-cp37m-manylinux2014_x86_64.whl (721 kB)
INFO: pip is looking at multiple versions of regex to determine which version is compatible with other requirements. This could take a while.