[Distutils] PEP 517: Build system API

Fri Nov 25 09:23:47 EST 2016

actually editable installs can be made uninstallable trivially

in gumby-elf i would create a fake wheel with files inside to facilitate
the path building for namespaces,
and a local version number (so pip would create my exe files and
uninstall clean)


-- Ronny
On 24.11.2016 01:23, Daniel Holth wrote:
>
> I wouldn't be afraid of editable installs. They are trivial and
> involve building the package in place and putting a .pth file where it
> will be noticed. Specify editable packages can't necessarily be
> uninstalled in a standard way and you are done.
>
> The bespoke build tool tells pip where the package root is (where
> .dist-info will be written), usually . or ./src, then pip does .pth.
>
>
> On Wed, Nov 23, 2016, 17:16 Chris Barker <chris.barker at noaa.gov
> <mailto:chris.barker at noaa.gov>> wrote:
>
>     On Wed, Nov 23, 2016 at 6:35 AM, Thomas Kluyver
>     <thomas at kluyver.me.uk <mailto:thomas at kluyver.me.uk>> wrote:
>      
>
>         Questions:
>         1. Editable installs. The PEP currenly specifies a hook to do an
>         editable install (like 'pip install -e' or 'setup.py develop')
>         into a
>         given prefix. I don't think that specifying a prefix is
>         sufficient to
>         cover '--user' installation, which uses a different install
>         scheme,
>         especially on Windows and OSX framework builds. We can:
>         a. Add an extra parameter 'user' to the hook, to override the
>         prefix and
>         do a user install.
>         b. Leave it as is, and do not support editable user
>         installation (which
>         would make me sad, as I do editable user installs regularly)
>
>
>     Please, please, let's figure SOMETHING our here - editable
>     installs (or "develop" installs) are a critical tool. Frankly, I
>     don't know how anyone can develop a package without them.
>
>     Back in the day I struggle mightily with kludging sys.path, and,
>     relative imports that never really worked right, and on and on --
>     it SUCKED.
>
>     Then I discovered setuptools develop mode -- yeah! IN fact, I
>     don't think I'd ever use setuptools at all if I didn't need it to
>     get develop mode!
>
>         c. Decide that editable installs are too fiddly to
>         standardise, and
>         leave it to users to invoke a tool directly to do an editable
>         install.
>
>
>     Not sure what that means -- does that mean that you couldn't get
>     an editable isntall with pip? but rather you would do:
>
>     setup.py develop   if you had setuptools as your build system, and 
>
>     some_other_command  if you had some other build tool?
>
>     Not too bad, but why not have a standard way to invoke develop
>     mode? If the tool can support it, why not have a way for pip to
>     tell an arbitrary build system to "please install this package in
>     develop mode"
>
>     On the other hand:
>
>     I've always thought we were moving toward proper separation of
>     concerns, in which case, pip should be focused on resolving
>     dependencies and finding and installing packages. 
>
>     Should it even be possible to build and install a package from
>     source with pip?
>
>     But if it is, then it might as well support editable installs as well.
>
>     The complication I see here is that a tool can't know how to
>     install in editable mode unless it knows about the python
>     environment it it running in -- which is easy for a tool built
>     with python, but a problem for a tool written some other way.
>
>     However, I see from PEP 517:
>
>
>     The build backend object is expected to have attributes which
>     provide some or all of the following hooks. The
>     commonconfig_settings argument is described after the individual
>     hooks:
>
>     def get_build_requires(config_settings):
>         ...
>
>
>     So I guess we can count on a Python front end, at least, so 1(a)
>     should be doable.
>
>     In fact, is the user-install issue any different for editable
>     installs than regular ones?
>
>     -CHB
>
>
>
>
>
>
>
>      
>
>
>
>      
>
>         2. Dash vs. underscore, bikeshed reloaded! Currently,  the
>         table name
>         uses a dash: [build-system], but the key added by PEP 517 uses an
>         underscore: build_backend. This seems a bit messy. I propose
>         that we
>         change build_backend to build-backend for consistency. Dashes and
>         underscores can both be used in a TOML key without needing
>         quoting.
>
>         Thanks,
>         Thomas
>         _______________________________________________
>         Distutils-SIG maillist  -  Distutils-SIG at python.org
>         <mailto:Distutils-SIG at python.org>
>         https://mail.python.org/mailman/listinfo/distutils-sig
>
>
>
>
>     -- 
>
>     Christopher Barker, Ph.D.
>     Oceanographer
>
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>
>     Chris.Barker at noaa.gov <mailto:Chris.Barker at noaa.gov>
>     _______________________________________________
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>     <mailto:Distutils-SIG at python.org>
>     https://mail.python.org/mailman/listinfo/distutils-sig
>
>
>
> _______________________________________________
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