For historical reasons, we still have a '/usr/bin/python' that is Python 2 on our Ubuntu 22.04 machines. Yes, we know, Python 2 isn't supported any more, but our users have had more than a decade where /usr/bin/python was Python 2 and while Ubuntu continued to ship a Python 2, we didn't feel like breaking their '#!/usr/bin/python' lines in scripts by either removing /usr/bin/python or making it Python 3. That option ran out in Ubuntu 24.04, which doesn't ship any Python 2 packages and so provides no native way to have a Python 2 /usr/bin/python (you can make a symlink to your own version of Python 2, if you really insist). In my entry on the state of Python in Ubuntu 24.04, I speculated that we might wind up with /usr/bin/python existing and being Python 3 in Ubuntu 26.04. With more time and more water under the bridge, I think we're fairly likely to do that or even move faster, partly because there are forces pushing reasonably strongly in that direction.

One of the things that I've been doing is watching for things running '/usr/bin/python' on our current login servers, because those things are going to break when we start upgrading them from Ubuntu 22.04 to Ubuntu 24.04 and I'd like to warn people in advance. In doing this, I found a number of people who seemed to every now and then run '/usr/bin/python' in a VSCode environment. Now, I rather doubt that people who are using VSCode are writing Python 2 programs here in 2024. Instead, I think it's much more likely that something in their VSCode environment is invoking '/usr/bin/python' and expecting to get Python 3.

Here in 2024, I suspect that this is a perfectly reasonable expectation and almost always works out for whatever VSCode related bit is doing it. Python 2 has been unsupported for four years and probably almost all Linux systems with a /usr/bin/python have it being Python 3 (this has been the situation on Fedora Linux for some time, for example). I also suspect that most Linux systems do have a /usr/bin/python. We are the weird outliers, and as weird outliers we can expect things to not work; at first a few things, and then more things as the assumption that '/usr/bin/python' is the way you get Python 3 becomes embedded in more and more software.

(I suspect that VSCode is not the only thing doing this on our systems, merely the one that's most visible to me right now.)

Having written this entry, I'm now reconsidering our schedule. As far as I can tell, we have low usage of /usr/bin/python today, although my checks aren't necessarily comprehensive, which means that relatively few people will be affected by a change to what it is. So rather than waiting until Ubuntu 26.04 or later to make /usr/bin/python be Python 3, perhaps we should wait only six months or so after we roll out Ubuntu 24.04 before switching from having no /usr/bin/python (and any remaining people having their scripts fail to run) to having it be Python 3. The result would probably be better for both people and programs.

PS: The simple answer to why not immediately switch /usr/bin/python to Python 3 when we move to Ubuntu 24.04 is that the error messages people will get for /usr/bin/python being missing are likely to be clearer than the ones they would get from running Python 2 code under Python 3.