Drop support for Python 2.6?

[Riccardo Murri]

Dear GC3Pie users,

it has been increasingly complicated to support Python 2.6 in GC3Pie
releases, as OpenStack and other major components of the Python
ecosystem are now supporting only Python >=2.7. In addition, dropping
Python 2.6 is a move we would have to do anyway when we start working
towards Python 3.x support (many 3.x constructs were backported to Py
2.7 but not 2.6).

As far as I understand, Python 2.6 is currently still the default Python
on CentOS 6.x and 7.x, and simply forcing a system-wide upgrade breaks
basic system utilities (including `yum`). There seem to be at least two
viable options to get Python 2.7 properly installed on a CentOS system:

* Use Anaconda Python2 [1] ("miniconda" is enough for GC3Pie)
* Use CentOS/RHEL "software collections" [2], [3]

Is there anyone running GC3Pie on CentOS for whom neither of the two
alternatives listed above would be practical?

[1]: https://www.continuum.io/downloads
[2]: https://wiki.centos.org/AdditionalResources/Repositories/SCL
[3]: https://wiki.centos.org/SpecialInterestGroup/SCLo/CollectionsList

Ciao,
R

--
Riccardo Murri, Schwerzenbacherstrasse 2, CH-8606 Nänikon, Switzerland

[Riccardo Murri]

Dear GC3Pie users,

I have received little feedback on the suggestion to drop support for
Python 2.6, and that all agreed with dropping.

Additionally, `pip` is dropping support for Python 2.6 in release 9.0;
see https://github.com/pypa/pip/issues/3955 . Without `pip`'s automated
resolution of dependencies, installation of GC3Pie on Python 2.6 becomes
too cumbersome -- it's just easier to install Python 2.7.

Therefore, release 2.5 of GC3Pie will be the last one to support Python 2.6.