On Sun, Aug 25, 2013 at 4:32 PM, Paul Moore <p.f.mo...@gmail.com> wrote: > On 25 August 2013 20:53, PJ Eby <p...@telecommunity.com> wrote: >> >> FWIW, I would also note that if you use easy_install to install >> anything, you are quite possibly using multi-version installs without >> realizing it. (The __main__.__requires__ API is used in >> easy_install-generated script wrappers, so there isn't any way you'd >> know about it without paying specific attention.) > > > Unless I'm missing something, I suspect that this over-counts the number of > people using multi-version, in the sense that many (the majority?) of > wrapper scripts using multi-version do not actually need to,because the > users never install more than one version. And quite likely don't even know > that they could.
That's just it: if you install two programs, one of which needs CherryPy 2 and the other CherryPy 3, then with easy_install this just works, without you having any idea that you even have more than one version installed, unless you for some reason choose to look into it. Thus, you don't have to know you have multiple versions installed; it can trivially happen by way of dependencies you aren't paying attention to. The more things you install, the more likely it is you have two versions hanging around. (The main limiting factor on conflicts isn't a choice to install multiple versions, it's the relative dearth of pinned versions and upper limits on version numbers. If everything just specifies minimum versions, you'll end up using the latest version for everything as the default version. It's only if a package pins or limits a dependency that any conflict is possible to begin with.) _______________________________________________ Distutils-SIG maillist - Distutils-SIG@python.org http://mail.python.org/mailman/listinfo/distutils-sig
