On 31 Jul 2013 08:49, "Vinay Sajip" <vinay_sa...@yahoo.co.uk> wrote: > > I'm looking at PEP 426 specifications for installation hooks and wondering > whether we need to tighten up the specification a little. > > My concern stems from the fact that hook code needs to be installed along > with other code - at least, the code for preuninstall hooks needs to be in > the installed code. As it's "only" hook code, the naming of modules which > contain it may not be done as carefully as the substantive modules and > packages in a distribution.
It's installed along with everything else, why would anyone assume they can ignore naming conflicts? If they do, then it's either a bug or a mutual incompatibility between affected distributions (just like other accidental name conflicts). >However, if multiple distributions were to put > their hooks in a "hooks.py" module, which might seem the simplest thing to > do, that could lead to problems: if these hook modules get written to site- > packages, the hooks.py from a later installed distribution would override > that from an earlier installed distribution. > > Possible solutions: > > 1. Constrain the specification so that each distribution must put hook code > in a subpackage of one of their main packages. This will affect any > distribution that consists only of modules and which has no packages, as the > authors will have to create a package just for the hook code. Why? If it's a single module that needs install hooks for some reason, the hook implementations can just go in there along with everything else (assuming they're not invoking a generic hook from a dependency). The names can be prefixed with an underscore to indicate they're not part of the regular API. > 2. Constrain the specification so that hook code is segregated to a single > module, perhaps specified by a "hook_module" key in the "install_hooks" > dict, which is written to the .dist-info directory. An installer could add > the .dist-info to sys.path before resolving/importing. The code in the hooks > module could invoke any code it needed from the main body of code in the > distribution. > > Is my concern a valid one? If so, can I please have comments/suggestions > about how to address it? Hook code is just normal code in the installed distribution (or a dependency). That's why there are deliberately no preinstall or postuninstall hooks - I don't want to come up with a new scheme for running code that hasn't been installed. Cheers, Nick. > > Regards, > > Vinay Sajip > > > _______________________________________________ > Distutils-SIG maillist - Distutils-SIG@python.org > http://mail.python.org/mailman/listinfo/distutils-sig
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