Support installation when running from an uninstalled Python

[tshepang]

BPO	12246
Nosy	@pfmoore, @tarekziade, @merwok, @bitdancer
Files	create-dir-if-nonexistent.diff display-warning.diff display-warning_try2.diff display_warning_with_test.patch: based on review of previous patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = 'https://github.com/merwok'
closed_at = <Date 2014-03-13.03:34:47.140>
created_at = <Date 2011-06-02.20:09:01.973>
labels = ['type-feature']
title = 'Support installation when running from an uninstalled Python'
updated_at = <Date 2014-03-13.03:34:47.140>
user = 'https://bugs.python.org/tshepang'

bugs.python.org fields:

activity = <Date 2014-03-13.03:34:47.140>
actor = 'eric.araujo'
assignee = 'eric.araujo'
closed = True
closed_date = <Date 2014-03-13.03:34:47.140>
closer = 'eric.araujo'
components = ['Distutils2']
creation = <Date 2011-06-02.20:09:01.973>
creator = 'tshepang'
dependencies = []
files = ['22223', '22259', '22267', '22277']
hgrepos = []
issue_num = 12246
keywords = ['patch']
message_count = 22.0
messages = ['137495', '137531', '137536', '137537', '137538', '137539', '137547', '137570', '137639', '137670', '137671', '137708', '137709', '137710', '137715', '137746', '137768', '137951', '138107', '138108', '138131', '147500']
nosy_count = 7.0
nosy_names = ['paul.moore', 'tarek', 'eric.araujo', 'r.david.murray', 'alexis', 'tshepang', 'python-dev']
pr_nums = []
priority = 'normal'
resolution = 'out of date'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue12246'
versions = ['Python 3.3']

[tshepang]

If I happen to not have the directory, $PREFIX/python3.3/site-packages, I get an erroneous message telling me that I don't write permissions.

[merwok]

This looks like an invalid bug to me; Python itself creates the site-packages directory, with a README file if I remember correctly. If the sysadmin removes the directory, it’s their problem, not a Python bug. Do you agree?

[tarekziade]

This is probably because Tshepang works in a dev environment.

I think we should have a nice message like "The installation path xxx seems not to exist, aborting installation"

[merwok]

Hm, in my dev environment (checkout of 3.3), site-packages exists.

[tarekziade]

Strange, you should get a /usr/[local]/lib/python3.3/site-packages when you just run "./configure; make"

It looks like you have a dev environment that has installed some stuff

[tarekziade]

s/should get/should not get/

[merwok]

Ah, I understand; I have a $srcdir/Lib/site-packages directory, but packaging wants to install into $prefix/site-packages, which does not exist. +1 to adding a nice message. Tshepang, would you like to update your patch?

[tshepang]

On Fri, 2011-06-03 at 16:18 +0000, Éric Araujo wrote:

Éric Araujo <merwok@netwok.org> added the comment:

Ah, I understand; I have a $srcdir/Lib/site-packages directory, but packaging wants to install into $prefix/site-packages, which does not exist. +1 to adding a nice message. Tshepang, would you like to update your patch?

Why not just create the directory, instead of print the warning? Is
there any harm?

[merwok]

We do not want to create a directory under $prefix before installation. This would be a sort of dirty half-installation. When you have an uninstalled, unconfigured Python, you cannot install modules without giving a prefix option: this sounds good to me.

[tshepang]

But this part of the code runs only when you want to install a 3rd party module isn't it? What you are proposing simply adds a delay, for the use will have to then add that directory manually. Or is there something I'm missing here?

[tshepang]

s/use/user

[bitdancer]

I'm not sure I understand your confusion, but perhaps what you are missing is that we don't support installing 3rd party packages inside a source tree, only into an installed Python, and installing Python creates the site-packages directory in $prefix.

[tshepang]

Are there cases where my patch would result in site-packages directory installed in an unwanted place?

[bitdancer]

Yes. If the directory gets created without Python being installed, then you don't have a working python installation. Assuming we are talking about site-packages. I have no idea what purelib is or anything about the packaging internals.