Installing wheels does not respect --install-option="--prefix=..."

[cswarth]

Similar to #1641, the latest development pip does not respect attempts to install packages in alternate location if installing from a wheel.

Using pip built from github sources today.

$ pip --version
pip 6.1.0.dev0 from /home/cwarth/.local/lib/python2.7/site-packages/pip-6.1.0.dev0-py2.7.egg (python 2.7)

Installing from a wheel fails.

$ pip   install --install-option="--prefix=/home/cwarth/tmp" --no-deps   -U -I seqmagick
Collecting seqmagick
  Using cached seqmagick-0.5.0-py2-none-any.whl
Installing collected packages: seqmagick

  Exception:
  Traceback (most recent call last):
    File "/home/cwarth/.local/lib/python2.7/site-packages/pip-6.1.0.dev0-py2.7.egg/pip/basecommand.py", line 232, in main
      status = self.run(options, args)
    File "/home/cwarth/.local/lib/python2.7/site-packages/pip-6.1.0.dev0-py2.7.egg/pip/commands/install.py", line 347, in run
      root=options.root_path,
    File "/home/cwarth/.local/lib/python2.7/site-packages/pip-6.1.0.dev0-py2.7.egg/pip/req/req_set.py", line 549, in install
      **kwargs
    File "/home/cwarth/.local/lib/python2.7/site-packages/pip-6.1.0.dev0-py2.7.egg/pip/req/req_install.py", line 751, in install
      self.move_wheel_files(self.source_dir, root=root)
    File "/home/cwarth/.local/lib/python2.7/site-packages/pip-6.1.0.dev0-py2.7.egg/pip/req/req_install.py", line 960, in move_wheel_files
      isolated=self.isolated,
    File "/home/cwarth/.local/lib/python2.7/site-packages/pip-6.1.0.dev0-py2.7.egg/pip/wheel.py", line 234, in move_wheel_files
      clobber(source, lib_dir, True)
    File "/home/cwarth/.local/lib/python2.7/site-packages/pip-6.1.0.dev0-py2.7.egg/pip/wheel.py", line 205, in clobber
      os.makedirs(destdir)
    File "/usr/lib/python2.7/os.py", line 150, in makedirs
      makedirs(head, mode)
    File "/usr/lib/python2.7/os.py", line 150, in makedirs
      makedirs(head, mode)
    File "/usr/lib/python2.7/os.py", line 157, in makedirs
      mkdir(name, mode)
  OSError: [Errno 13] Permission denied: '/usr/local/lib/python2.7/dist-packages/build'

Avoiding the wheel works fine.

$ pip   install --install-option="--prefix=/home/cwarth/tmp" --no-use-wheel --no-deps   -U -I seqmagick
Collecting seqmagick
  Using cached seqmagick-0.5.0.tar.gz
Installing collected packages: seqmagick
  Running setup.py install for seqmagick
    Installing seqmagick script to /home/cwarth/tmp/bin
Successfully installed seqmagick

[cswarth]

I don't actually know if this is a distutils problem or a pip problem. I'm posting it here as a starting point because of the similarities with #1641

[qwcode]

closing as dupe to #1716