Cleaned up pip backtracking

Signed-off-by: Andreas Maier <[email protected]>

dev-requirements.txt

@@ -11,19 +11,33 @@
 
 # Indirect dependencies that must be handled early:
 
-# tox and flake8 have requirements on importlib-metadata
-importlib-metadata>=1.1.0,<4.3; python_version <= '3.7'
+# importlib-metadata
+# importlib.metadata was integrated to standard Python in Python 3.8, so as a
+#   package it is only needed in Python<=3.7.
+# importlib-metadata 5.0 removed interfaces, and in the version integrated to
+#   Python, that was done in Python 3.12 which integrated importlib-metadata 6.5.
+# flake8 4.0/5.0 requires importlib-metadata>=1.1.0,<4.3 on Python<=3.7. flake8
+#   pins importlib-metadata (at least) because flake8 <6.0 has not yet adjusted
+#   to the removed interfaces in importlib-metadata 5.0 / Python 3.12.
+# virtualenv 20.16.3 started requiring importlib-metadata>=4.8.3
+# virtualenv 20.22.0 started requiring importlib-metadata>=6.4.1
+importlib-metadata>=2.1.3,<5; python_version == '3.6'
+importlib-metadata>=5.0.0; python_version == '3.7'
 
 
 # Direct dependencies:
 
 # Coverage reporting (no imports, invoked via coveralls script):
-coverage>=5.0
+# coveralls 3.3.0 pins coverage to <7.0, causing pip backtracking to happen. Pinning
+#   it to <7.0 in this file saves the time for backtracking, but requires to
+#   occasionally check for new versions of coveralls without pinning.
+coverage>=5.0,<7.0
 pytest-cov>=2.7.0
 coveralls>=3.3.0
 
 # Safety CI by pyup.io
-safety>=2.2.0
+# safety 2.3.5 (only) requires packaging>=21.0,<22.0 and causes pip backtracking of tox
+safety>=2.2.0,!=2.3.5
 # safety 2.2.0 requires dparse>=0.6.2
 dparse>=0.6.2
 
@@ -37,25 +51,25 @@ PyYAML>=5.3.1
 
 # Tox
 # tox 3.17 requires six>=1.14.0 - covered in requirements.txt
-# tox 3.21 requires importlib-metadata>=0.12 on py<3.8
+# tox 3.21 requires importlib-metadata>=0.12 on Python<=3.7
 tox>=3.21.0
 
 # Sphinx (no imports, invoked via sphinx-build script):
 # Keep in sync with rtd-requirements.txt
 
-# Sphinx 4.0.0 breaks autodocsumm and needs to be excluded
-# Sphinx <4.2.0 fails on Python 3.10 because it tries to import non-existing
-#   types.Union. This also drives docutils>=0.14.
-# Sphinx pins docutils to <0.18 (some versions even to <0.17) but the package
-#   version resolver in the pip version used on py27 ignores package dependencies
-Sphinx>=4.2.0
-docutils>=0.16,<0.17
+# sphinx-rtd-theme 2.0.0 requires Sphinx>=5,<8
+# sphinx 4.0.0,4.0.1 (only) pin Jinja2 to <3.0
+# sphinx 4.4.0 started requiring importlib-metadata>=4.4
+Sphinx>=4.0.2,<4.4.0; python_version <= '3.7'
+Sphinx>=4.0.2; python_version >= '3.8'
+docutils>=0.16
 sphinx-git>=10.1.1
-GitPython>=2.1.1; python_version == '3.6'
-GitPython>=3.1.37; python_version >= '3.7'
+GitPython>=2.1.1; python_version <= '3.7'
+GitPython>=3.1.41; python_version >= '3.8'
 sphinxcontrib-fulltoc>=1.2.0
 sphinxcontrib-websupport>=1.1.2
-Pygments>=2.7.4
+Pygments>=2.7.4; python_version <= '3.7'
+Pygments>=2.15.0; python_version >= '3.8'
 sphinx-rtd-theme>=1.0.0
 # Babel 2.7.0 fixes an ImportError for MutableMapping which starts failing on Python 3.10
 Babel>=2.9.1
@@ -65,9 +79,9 @@ Babel>=2.9.1
 # Pylint 2.10/ astroid 2.7 addresses issue https://github.com/PyCQA/pylint/issues/4118
 # Pylint 2.14 / astroid 2.11 support wrapt 1.14 which is required for Python 3.11, but in addition:
 # Pylint 2.15 / astroid 2.12 is needed to circumvent issue https://github.com/PyCQA/pylint/issues/7972 on Python 3.11
-pylint>=2.13.0; python_version <= '3.6'
+pylint>=2.13.0; python_version == '3.6'
 pylint>=2.15.0; python_version >= '3.7'
-astroid>=2.11.0; python_version <= '3.6'
+astroid>=2.11.0; python_version == '3.6'
 astroid>=2.12.4; python_version >= '3.7'
 # astroid 2.13.0 uses typing-extensions on Python<3.11 but misses to
 #   require it on 3.10. See https://github.com/PyCQA/astroid/issues/1942
@@ -83,22 +97,33 @@ isort>=4.3.8
 # Pylint 2.14 uses tomlkit>=0.10.1 and requires py>=3.7
 tomlkit>=0.10.1
 # dill is used by pylint >=2.13
-dill>=0.3.4; python_version <= '3.6'
+dill>=0.3.4; python_version == '3.6'
 dill>=0.3.6; python_version >= '3.7'
 # platformdirs is used by pylint starting with its 2.10
 platformdirs>=2.2.0
 
 # Flake8 and dependents (no imports, invoked via flake8 script):
-# flake8 4.0.0 fixes an AttributeError on Python 3.10.
-# flake8 5.0.4 requires importlib-metadata>=1.1.0,<4.3 on py<3.8
-flake8>=4.0.0
-mccabe>=0.6.0
-pycodestyle>=2.8.0
-pyflakes>=2.4.0
+# flake8 6.0.0 dropped support for Python<=3.7
+# flake8 4.0.0 fixed an AttributeError on Python 3.10
+# flake8 4.0/5.0 requires importlib-metadata>=1.1.0,<4.3 on Python<=3.7. flake8
+#   pins importlib-metadata (at least) because flake8 <6.0 has not yet adjusted
+#   to the removed interfaces in importlib-metadata 5.0 / Python 3.12.
+# flake8 3.9.2 requires pyflakes>=2.3.0,<2.4.0
+flake8>=3.8.0,<4.0.0; python_version <= '3.7'
+flake8>=3.8.0; python_version >= '3.8' and python_version <= '3.9'
+flake8>=4.0.0; python_version >= '3.10'
+mccabe>=0.6.0; python_version <= '3.9'
+mccabe>=0.7.0; python_version >= '3.10'
+pycodestyle>=2.7.0; python_version <= '3.7'
+pycodestyle>=2.8.0; python_version >= '3.8' and python_version <= '3.9'
+pycodestyle>=2.9.0; python_version >= '3.10'
+pyflakes>=2.3.0; python_version <= '3.7'
+pyflakes>=2.4.0; python_version >= '3.8' and python_version <= '3.9'
+pyflakes>=2.5.0; python_version >= '3.10'
 entrypoints>=0.3.0
 
 # Twine (no imports, invoked via twine script):
-twine>=1.8.1
+twine>=3.0.0
 # readme-renderer 23.0 has made cmarkgfm part of extras (it fails on Cygwin)
 readme-renderer>=23.0
 

minimum-constraints.txt

@@ -40,16 +40,15 @@ pytest==7.0.0
 # Install test direct dependencies:
 
 # virtualenv
-virtualenv==20.1.0
+virtualenv==20.2.1
 
 # six (used by virtualenv, tox, probably others)
 six==1.14.0
 
 
 # Indirect dependencies for test (must be consistent with test-requirements.txt, if present)
 
-# packaging (used by pytest)
-# Packaging 21.0 is required by safety 2.2.0
+# packaging (used by pytest, safety)
 packaging==21.0
 
 # pluggy (used by pytest, tox)
@@ -59,7 +58,8 @@ pluggy==0.13.1
 # Indirect dependencies that must be handled early (must be consistent with dev-requirements.txt)
 
 # tox and flake8 have requirements on importlib-metadata
-importlib-metadata==1.1.0; python_version <= '3.7'
+importlib-metadata==2.1.3; python_version == '3.6'
+importlib-metadata==5.0.0; python_version == '3.7'
 
 
 # Direct dependencies for development (must be consistent with dev-requirements.txt)
@@ -93,37 +93,43 @@ PyYAML==5.3.1
 tox==3.21.0
 
 # Sphinx (no imports, invoked via sphinx-build script):
-Sphinx==4.2.0
+Sphinx==4.0.2
 docutils==0.16
 sphinx-git==10.1.1
-GitPython==2.1.1; python_version == '3.6'
-GitPython==3.1.41; python_version >= '3.7'
+GitPython==2.1.1; python_version <= '3.7'
+GitPython==3.1.41; python_version >= '3.8'
 sphinxcontrib-fulltoc==1.2.0
 sphinxcontrib-websupport==1.1.2
-Pygments==2.7.4; python_version == '3.6'
-Pygments==2.15.0; python_version >= '3.7'
+Pygments==2.7.4; python_version <= '3.7'
+Pygments==2.15.0; python_version >= '3.8'
 sphinx-rtd-theme==1.0.0
 Babel==2.9.1
 
 # PyLint (no imports, invoked via pylint script) - does not support py3:
-pylint==2.13.0; python_version <= '3.6'
+pylint==2.13.0; python_version == '3.6'
 pylint==2.15.0; python_version >= '3.7'
-astroid==2.11.0; python_version <= '3.6'
+astroid==2.11.0; python_version == '3.6'
 astroid==2.12.4; python_version >= '3.7'
 typed-ast==1.4.0; python_version >= '3.6' and python_version <= '3.7' and implementation_name=='cpython'
 lazy-object-proxy==1.4.3
 wrapt==1.14
 isort==4.3.8
 tomlkit==0.10.1
-dill==0.3.4; python_version <= '3.6'
+dill==0.3.4; python_version == '3.6'
 dill==0.3.6; python_version >= '3.7'
 platformdirs==2.2.0
 
 # Flake8 and dependents (no imports, invoked via flake8 script):
-flake8==4.0.0
-mccabe==0.6.0
-pycodestyle==2.8.0
-pyflakes==2.4.0
+flake8==3.8.0; python_version <= '3.9'
+flake8==4.0.0; python_version >= '3.10'
+mccabe==0.6.0; python_version <= '3.9'
+mccabe==0.7.0; python_version >= '3.10'
+pycodestyle==2.7.0; python_version <= '3.7'
+pycodestyle==2.8.0; python_version >= '3.8' and python_version <= '3.9'
+pycodestyle==2.9.0; python_version >= '3.10'
+pyflakes==2.3.0; python_version <= '3.7'
+pyflakes==2.4.0; python_version >= '3.8' and python_version <= '3.9'
+pyflakes==2.5.0; python_version >= '3.10'
 entrypoints==0.3.0
 
 # Twine (no imports, invoked via twine script):

test-requirements.txt

@@ -17,8 +17,13 @@ pytest>=7.0.0
 # Install test direct dependencies:
 
 # virtualenv
-# tox 3.21.0 requires virtualenv!=20.0.[0-7],>=16.0.0 and requires py>=3.5
-virtualenv>=20.1.0
+# virtualenv 20.18.0 dropped support for Python 3.6
+# virtualenv 20.16.3 started requiring importlib-metadata>=4.8.3, but
+#   flake8 4.0/5.0 requires importlib-metadata>=1.1.0,<4.3 on Python<=3.7
+# virtualenv 20.2.1 started removing the prior pinning of importlib-metadata to <3
+# tox 3.21.0 requires virtualenv!=20.0.[0-7],>=16.0.0 and requires Python >=3.5
+virtualenv>=20.2.1,<20.16.3; python_version == '3.6'
+virtualenv>=20.2.1; python_version >= '3.7'
 
 # six (also used by virtualenv, tox, probably others)
 # virtualenv 20.0 requires six>=1.12.0 on py>=3.8
@@ -29,8 +34,7 @@ six>=1.14.0
 # Indirect dependencies with special constraints:
 
 # packaging (used by pytest)
-# safety 2.3.5 started pinning packaging to <22.0 and requires >=21.0
-packaging>=21.0,<22.0
+packaging>=21.0
 
 # pluggy (used by pytest, tox)
 # Pluggy 0.12.0 has a bug causing pytest plugins to fail loading on py38