This adds constraints files. Like requirements files constraints files
control what version of a package is installed, but unlike
requirements files this doesn't itself choose to install the package.
This allows things that aren't explicitly desired to be constrained if
and only if they are installed.
We're actually pinning down a fairly specific grammar now, so lets
make it official. All options are at the end, and only options get
quoting. I've also tweaked some of the existing examples to make the
existing grammar features (that I know people use) clearer - like
spaces between requirements and version specifiers.
With wheel autobuilding in place a release blocker is some granular
way to opt-out of wheels for known-bad packages. This patch introduces
two new options: --no-binary and --only-binary to control what
archives we are willing to use on both a global and per-package basis.
This also closes#2084
Building wheels before installing elminates a cause of broken environments -
where install fails after we've already installed one or more packages.
If a package fails to wheel, we run setup.py install as normally.
This allows lines such as the following to exist in requirements files:
INITools==0.2 --install-options="--prefix=/opt"
virtualenv>=1 --global-options="--no-user-cfg"
In addition, the requirements file parser was overhauled with simplicity
and clarity in mind.
This is needed for setup-requires, since without it its possible
to cause installation to fail in sort-circuit scenarios such as
the added functional test case demonstrates.
using object that have the same name as submodules as the weird effect
of makeing `import pip.commands.<something> as <anothername>` fail with
a key error. This fixes it by renamin commands as command_dict and fixin
a few imports to accomodate.
Related to #2149
It's now possible to specify requirements markers in requirements.
Examples::
futures; python_version < '2.7'
mock; python_version < '3.3'
nose
ordereddict; python_version < '2.7'
unittest2; python_version < '2.7'
The separator is "; ". For convinience, ";" alone is also supported, but
no in URLs. The ";" character is a legit and common character in an URL.
Example of valid URL without markers::
http://foo.com/?p=bar.git;a=snapshot;h=v0.1;sf=tgz
Example of URL with markers::
http://foo.com/?p=bar.git;a=snapshot;h=v0.1;sf=tgz; python_version < '3.3'
