[Distutils] Mystery solved
jim at zope.com
Tue Jul 11 21:56:48 CEST 2006
On Jul 11, 2006, at 2:07 PM, Phillip J. Eby wrote:
> At 11:50 AM 7/11/2006 -0400, Jim Fulton wrote:
>> OK that's an interesting point wrt possible misspellings. If you can
>> find the package via the find links, but not via the index, that
>> seems to me to be a pretty good indication that this is not a
>> misspelling. This is the case I'm worried about. If the package
>> can't be found anywhere, then I agree that a warning is warranted.
> The interesting question there is, should the fallback scan still
> take place in the absence of the warning? If it *does* take place,
> then the reason for the scan (and delay) is unexplained. If it
> does *not* take place, then there is an undesirable change in
> Currently, if you have a package called "Bob's Incredible Package",
> this will be treated by easy_install as being spelled "Bob-s-
> Incredible-Package", and it will require a top-level index scan to
> find the right URL. It is also possible to have --find-links pages
> containing obsolete versions, while PyPI contains the latest
> version, so removing the scan doesn't seem to be a reasonable option.
> So, I will simply change the message to an "info" message stating
> that the index page couldn't be found (rather than a warning
> suggesting misspelling), *if* easy_install has previously seen at
> least one valid distribution file or link for the applicable
> project name.
>> The specific case, which I'll repeat from above, as clearly as I can,
>> is this:
>> - A user chooses not to store their software in an index.
>> - The user places distributions on a web server somewhere. This is
>> just a directory, it is not a valid index.
>> - The user points at their server using find-links
>> - The user has an installation and they want to check for newer
>> - The distributions that they are looking for newer versions of can
>> be found on the server that they name via find-links.
>> In this case, they will get a warning that the distribution they are
>> looking for couldn't be found on the index.
> Okay, this scenario is fixed by changing to an info message as
> described above.
>>> If you did that, however, it brings in the question of which of
>>> the --find-links URLs should be checked for a /projectname/
>>> subdirectory. All of them? Just the first one that finds a
>>> result? None of them, if some other criterion is met?
>> I would stop when a result is found.
> Even so, this means O(N x M) web hits, where N is the number of
> packages and M is the number of --find-links (including dependency
> links supplied by eggs installed so far). I don't think it's
> reasonable to hit so many non-existent URLs on non-index servers,
> and is impolite to the servers' operators. (For example, if they
> receive a daily report of all 404 errors from their web servers, as
> I do. This is pretty common on Red Hat boxes using logwatch, for
> It's particularly unfair since using e.g. http://
> peak.telecommunity.com/snapshots/ as a --find-links while
> installing, say TurboGears, would cause a whole host of "index"
> hits to subdirectories of that URL, even though none of them can or
> will be found.
> The fallout from this approach is far worse than any "screen
> scraping" issues we've had.
Isn't this the approach that's followed now? Aren't all of the find-
links searched as well as the index? I suppose you're referring to
the search for /projectname, which potentially doubles the number of
>> What is the use case for spreading distributions over multiple
>> servers? Do people really want to do that? I can see providing
>> multiple places to look, because different distributions might be on
>> different servers, but I don't see why distributions for a single
>> project should be spread over multiple servers.
> Platform-specific distributions may be provided by contributors to
> a project, rather than by the project's author; see, for example,
> Bob Ippolito's pages for distributing Mac OS X builds of popular
> Python packages. For this reason, you may have certain pages that
> you always want included in your --find-links, to be checked in
> addition to the normal indexes.
Jim Fulton mailto:jim at zope.com Python Powered!
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