Travis builds broken for Python 2.6

[Christian Boos]

Last night, the Travis builds for the stable branches failed because the Python 2.6 builds failed to install their required packages.

One of the last successful one was ​Build #354 / Job #3545.1:

DEPRECATION: Python 2.6 is no longer supported by the Python core team, please upgrade your Python. A future version of pip will drop support for Python 2.6
Collecting Genshi>=0.7
/home/travis/virtualenv/python2.6.9/lib/python2.6/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:318: SNIMissingWarning: An HTTPS request has been made, but the SNI (Subject Name Indication) extension to TLS is not available on this platform. This may cause the server to present an incorrect TLS certificate, which can cause validation failures. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#snimissingwarning.
  SNIMissingWarning
/home/travis/virtualenv/python2.6.9/lib/python2.6/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
Collecting lxml
Collecting twill==0.9.1
Collecting Pygments
  Using cached https://files.pythonhosted.org/packages/13/e5/6d710c9cf96c31ac82657bcfb441df328b22df8564d58d0c4cd62612674c/Pygments-2.3.1-py2.py3-none-any.whl
Collecting docutils
  Using cached https://files.pythonhosted.org/packages/50/09/c53398e0005b11f7ffb27b7aa720c617aba53be4fb4f4f3f06b9b5c60f28/docutils-0.14-py2-none-any.whl
Collecting textile
  Using cached https://files.pythonhosted.org/packages/dc/72/c4c0c86d27e1bd4027ae8881bb4ebd208d1232c8d091c0b2254fdc709d63/textile-3.0.3-py2.py3-none-any.whl
Collecting pytz
  Using cached https://files.pythonhosted.org/packages/f8/0e/2365ddc010afb3d79147f1dd544e5ee24bf4ece58ab99b16fbb465ce6dc0/pytz-2018.7-py2.py3-none-any.whl
Collecting Babel<2.6.0
  Using cached https://files.pythonhosted.org/packages/94/03/14e68ad12e771a79cf96792f7158d68a7b3d8c7b2badf39e9ef1f65b57d6/Babel-2.5.3-py2.py3-none-any.whl
Collecting html5lib>=0.999999999 (from textile)
  Using cached https://files.pythonhosted.org/packages/a5/62/bbd2be0e7943ec8504b517e62bab011b4946e1258842bc159e5dfde15b96/html5lib-1.0.1-py2.py3-none-any.whl
Requirement already satisfied: ordereddict>=1.1; python_version == "2.6" in /home/travis/virtualenv/python2.6.9/lib/python2.6/site-packages (from textile)
Requirement already satisfied: six in /home/travis/virtualenv/python2.6.9/lib/python2.6/site-packages (from textile)
Collecting webencodings (from html5lib>=0.999999999->textile)
  Using cached https://files.pythonhosted.org/packages/f4/24/2a3e3df732393fed8b3ebf2ec078f05546de641fe1b667ee316ec1dcf3b7/webencodings-0.5.1-py2.py3-none-any.whl
Installing collected packages: Genshi, lxml, twill, Pygments, docutils, webencodings, html5lib, textile, pytz, Babel
Successfully installed Babel-2.5.3 Genshi-0.7.1 Pygments-2.3.1 docutils-0.14 html5lib-1.0.1 lxml-4.2.5 pytz-2018.7 textile-3.0.3 twill-0.9.1 webencodings-0.5.1

We can see that the "older" packages are fetched from the cache.

The failing build says:

DEPRECATION: Python 2.6 is no longer supported by the Python core team, please upgrade your Python. A future version of pip will drop support for Python 2.6
Collecting Genshi>=0.7
/home/travis/virtualenv/python2.6.9/lib/python2.6/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:318: SNIMissingWarning: An HTTPS request has been made, but the SNI (Subject Name Indication) extension to TLS is not available on this platform. This may cause the server to present an incorrect TLS certificate, which can cause validation failures. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#snimissingwarning.
  SNIMissingWarning
/home/travis/virtualenv/python2.6.9/lib/python2.6/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
Collecting configobj
Collecting Pygments
  Using cached https://files.pythonhosted.org/packages/13/e5/6d710c9cf96c31ac82657bcfb441df328b22df8564d58d0c4cd62612674c/Pygments-2.3.1-py2.py3-none-any.whl
Collecting docutils
  Using cached https://files.pythonhosted.org/packages/50/09/c53398e0005b11f7ffb27b7aa720c617aba53be4fb4f4f3f06b9b5c60f28/docutils-0.14-py2-none-any.whl
Collecting textile
  Using cached https://files.pythonhosted.org/packages/dc/72/c4c0c86d27e1bd4027ae8881bb4ebd208d1232c8d091c0b2254fdc709d63/textile-3.0.3-py2.py3-none-any.whl
Collecting lxml
/home/travis/virtualenv/python2.6.9/lib/python2.6/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
  Downloading https://files.pythonhosted.org/packages/16/4a/b085a04d6dad79aa5c00c65c9b2bbcb2c6c22e5ac341e7968e0ad2c57e2f/lxml-4.3.0.tar.gz (2.5MB)
    100% |████████████████████████████████| 2.5MB 560kB/s 
    Complete output from command python setup.py egg_info:
    This lxml version requires Python 2.7, 3.4 or later.
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-ER22wI/lxml/
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/travis/virtualenv/python2.6.9/lib/python2.6/site-packages/pkg_resources/__init__.py", line 967, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/home/travis/virtualenv/python2.6.9/lib/python2.6/site-packages/pkg_resources/__init__.py", line 853, in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'Babel<2.6.0' distribution was not found and is required by the application
DEPRECATION: Python 2.6 is no longer supported by the Python core team, please upgrade your Python. A future version of pip will drop support for Python 2.6
Package     Version 
----------- --------
argparse    1.4.0   
funcsigs    1.0.2   
mock        2.0.0   
nose        1.3.7   
numpy       1.11.2  
ordereddict 1.1     
pbr         1.10.0  
pip         9.0.1   
py          1.4.31  
pytest      3.0.3   
setuptools  28.8.0  
six         1.10.0  
wheel       0.30.0a0

As it's an all or nothing thing, Genshi is not installed due to the failure to install Babel.

There's probably a way to point to the archive directly.

[Jun Omae]

We could pin the version of lxml for Python 2.6:

.travis.yml

@@ -148 +148 @@
       python -c 'from svn import core'
     fi
   - |
-    requires='Genshi>=0.7 lxml twill==0.9.1'
+    requires='Genshi>=0.7 twill==0.9.1'
+    case "$pyver" in
+      2.6) requires="$requires lxml<4.3.0" ;;
+      *)   requires="$requires lxml" ;;
+    esac
     if [ "$build" != minimum ]; then
       requires="$requires Pygments docutils textile pytz"
       case "$pyver" in

The same issue exists on 1.0-stable, ​Build #3548 - edgewall/trac - Travis CI.

[Christian Boos]

The build #3571 (e.g. ​Job #3573.1) for r16872 with the patch from comment:1 passed, as it managed to install lxml 4.2.6.

Looks like the Babel error was a transient one (Babel 2.5.3 got installed this time).

[Christian Boos]

Merged in r16873 on 1.2-stable which also has Python 2.6, but record-merge only on trunk (r16874) as we only have Python 2.7 there.