title: Cannot install lxml using pip
body: <p>I have tried to install lxml python library on Ubuntu 14.04 using <code>pip install lxml</code>.</p>
  
  <p>It have failed and the output was (brought only the end here):</p>
  
  <pre><code>...
  ...
  ...
  
  src/lxml/lxml.etree.c:8:22: fatal error: pyconfig.h: No such file or directory
  
   #include "pyconfig.h"
  
                        ^
  
  compilation terminated.
  
  error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
  </code></pre>
  
  <p>I have searched the problem and found that I should install some stuff using:</p>
  
  <p><code>apt-get install libxml2-dev libxslt-dev libxslt1-dev python-dev</code></p>
  
  <p>Then I have retried to install using <code>pip install lxml</code>. The installation failed again, now with a different error. Trying <code>pip --default-timeout=300 install lxml</code> changed nothing.</p>
  
  <p>The new error is:</p>
  
  <pre><code>...
  ...
  ...
  
  creating build/temp.linux-x86_64-2.7/src/lxml
  
  x86_64-linux-gnu-gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/libxml2 -I/tmp/pip_build_root/lxml/src/lxml/includes -I/usr/include/python2.7 -c src/lxml/lxml.etree.c -o build/temp.linux-x86_64-2.7/src/lxml/lxml.etree.o -w
  
  x86_64-linux-gnu-gcc -pthread -shared -Wl,-O1 -Wl,-Bsymbolic-functions -Wl,-Bsymbolic-functions -Wl,-z,relro -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -D_FORTIFY_SOURCE=2 -g -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security build/temp.linux-x86_64-2.7/src/lxml/lxml.etree.o -lxslt -lexslt -lxml2 -lz -lm -o build/lib.linux-x86_64-2.7/lxml/etree.so
  
  /usr/bin/ld: cannot find -lz
  
  collect2: error: ld returned 1 exit status
  
  error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
  
  ----------------------------------------
  Cleaning up...
  Command /usr/bin/python -c "import setuptools, tokenize;__file__='/tmp/pip_build_root/lxml/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-PVygtI-record/install-record.txt --single-version-externally-managed --compile failed with error code 1 in /tmp/pip_build_root/lxml
  Storing debug log for failure in /root/.pip/pip.log
  </code></pre>
  
  <p>Additional information from <code>/root/.pip/pip.log</code> file:</p>
  
  <pre><code>Exception information:
  Traceback (most recent call last):
    File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 122, in main
      status = self.run(options, args)
    File "/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 283, in run
      requirement_set.install(install_options, global_options, root=options.root_path)
    File "/usr/lib/python2.7/dist-packages/pip/req.py", line 1436, in install
      requirement.install(install_options, global_options, *args, **kwargs)
    File "/usr/lib/python2.7/dist-packages/pip/req.py", line 707, in install
      cwd=self.source_dir, filter_stdout=self._filter_install, show_stdout=False)
    File "/usr/lib/python2.7/dist-packages/pip/util.py", line 715, in call_subprocess
      % (command_desc, proc.returncode, cwd))
  InstallationError: Command /usr/bin/python -c "import setuptools, tokenize;__file__='/tmp/pip_build_root/lxml/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-Jj2y9w-record/install-record.txt --single-version-externally-managed --compile failed with error code 1 in /tmp/pip_build_root/lxml
  </code></pre>
  
  <p>However, I can install lxml by <code>apt-get install python-lxml</code>, and also install locally after downloading manually from lxml's website but I want to install using pip.</p>