title: How to fix error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
body: <p>I'm trying to install odoo on a fresh installation of Linux on a VirtualBox machine. I have entered in the commands found here as is: <a href="http://odoo-development.readthedocs.org/en/latest/install.html" rel="noreferrer">Odoo Development Read the Docs</a>. The following command is what prompts the error: command 'x86_64-linux-gnu-gcc' failed with exit status 1:</p>
  
  <pre><code>sudo pip install -r requirements.txt
  </code></pre>
  
  <p>So now I'm trying to solve the problem. I have gone to <a href="https://stackoverflow.com/questions/26053982/error-setup-script-exited-with-error-command-x86-64-linux-gnu-gcc-failed-wit">error: Setup script exited with error: command 'x86_64-linux-gnu-gcc' failed with exit status 1</a>,<a href="https://stackoverflow.com/questions/11094718/error-command-gcc-failed-with-exit-status-1-while-installing-eventlet">error: command 'gcc' failed with exit status 1 while installing eventlet</a> , and entered in the following commands. </p>
  
  <p>For the first link:</p>
  
  <pre><code>sudo apt-get install build-essential autoconf libtool pkg-config python-opengl python-imaging python-pyrex python-pyside.qtopengl idle-python2.7 qt4-dev-tools qt4-designer libqtgui4 libqtcore4 libqt4-xml libqt4-test libqt4-script libqt4-network libqt4-dbus python-qt4 python-qt4-gl libgle3 python-dev
  
  sudo easy_install greenlet
  
  sudo easy_install gevent
  
  sudo pip install -r requirements.txt
  
  error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
  </code></pre>
  
  <p>The Second Link:</p>
  
  <pre><code>sudo apt-get install python-dev
  sudo pip install -r requirements.txt
  </code></pre>
  
  <p>I still get the error. Then I tried:</p>
  
  <pre><code>sudo apt-get install libevent-dev
  sudo pip install -r requirements.txt
  
  error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
  </code></pre>
  
  <p>What am I doing wrong? </p>
  
  <p>Here is what happens after I enter the command:</p>
  
  <pre><code>$ sudo pip install -r requirements.txt
  Requirement already satisfied (use --upgrade to upgrade): Babel==1.3 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 1))
  Requirement already satisfied (use --upgrade to upgrade): Jinja2==2.7.3 in /usr/local/lib/python2.7/dist-packages (from -r requirements.txt (line 2))
  Requirement already satisfied (use --upgrade to upgrade): Mako==1.0.1 in /usr/local/lib/python2.7/dist-packages (from -r requirements.txt (line 3))
  Requirement already satisfied (use --upgrade to upgrade): MarkupSafe==0.23 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 4))
  Requirement already satisfied (use --upgrade to upgrade): Pillow==2.7.0 in /usr/local/lib/python2.7/dist-packages (from -r requirements.txt (line 5))
  Requirement already satisfied (use --upgrade to upgrade): Python-Chart==1.39 in /usr/local/lib/python2.7/dist-packages (from -r requirements.txt (line 6))
  Requirement already satisfied (use --upgrade to upgrade): PyYAML==3.11 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 7))
  Requirement already satisfied (use --upgrade to upgrade): Werkzeug==0.9.6 in /usr/local/lib/python2.7/dist-packages (from -r requirements.txt (line 8))
  Requirement already satisfied (use --upgrade to upgrade): argparse==1.2.1 in /usr/lib/python2.7 (from -r requirements.txt (line 9))
  Requirement already satisfied (use --upgrade to upgrade): decorator==3.4.0 in /usr/local/lib/python2.7/dist-packages (from -r requirements.txt (line 10))
  Requirement already satisfied (use --upgrade to upgrade): docutils==0.12 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 11))
  Requirement already satisfied (use --upgrade to upgrade): feedparser==5.1.3 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 12))
  Requirement already satisfied (use --upgrade to upgrade): gdata==2.0.18 in /usr/local/lib/python2.7/dist-packages (from -r requirements.txt (line 13))
  Requirement already satisfied (use --upgrade to upgrade): gevent==1.0.2 in /usr/local/lib/python2.7/dist-packages (from -r requirements.txt (line 14))
  Requirement already satisfied (use --upgrade to upgrade): greenlet==0.4.7 in /usr/local/lib/python2.7/dist-packages (from -r requirements.txt (line 15))
  Requirement already satisfied (use --upgrade to upgrade): jcconv==0.2.3 in /usr/local/lib/python2.7/dist-packages (from -r requirements.txt (line 16))
  Downloading/unpacking lxml==3.4.1 (from -r requirements.txt (line 17))
    Downloading lxml-3.4.1.tar.gz (3.5MB): 3.5MB downloaded
    Running setup.py (path:/tmp/pip-build-Hqt4sF/lxml/setup.py) egg_info for package lxml
      /usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'bugtrack_url'
        warnings.warn(msg)
      Building lxml version 3.4.1.
      Building without Cython.
      ERROR: /bin/sh: 1: xslt-config: not found
  
      ** make sure the development packages of libxml2 and libxslt are installed **
  
      Using build configuration of libxslt
  
      warning: no previously-included files found matching '*.py'
  Downloading/unpacking mock==1.0.1 (from -r requirements.txt (line 18))
    Downloading mock-1.0.1.tar.gz (818kB): 818kB downloaded
    Running setup.py (path:/tmp/pip-build-Hqt4sF/mock/setup.py) egg_info for package mock
  
      warning: no files found matching '*.png' under directory 'docs'
      warning: no files found matching '*.css' under directory 'docs'
      warning: no files found matching '*.html' under directory 'docs'
      warning: no files found matching '*.js' under directory 'docs'
  Downloading/unpacking ofxparse==0.14 (from -r requirements.txt (line 19))
    Downloading ofxparse-0.14.tar.gz (42kB): 42kB downloaded
    Running setup.py (path:/tmp/pip-build-Hqt4sF/ofxparse/setup.py) egg_info for package ofxparse
  
  Downloading/unpacking passlib==1.6.2 (from -r requirements.txt (line 20))
    Downloading passlib-1.6.2.tar.gz (408kB): 408kB downloaded
    Running setup.py (path:/tmp/pip-build-Hqt4sF/passlib/setup.py) egg_info for package passlib
  
  Downloading/unpacking psutil==2.2.0 (from -r requirements.txt (line 21))
    Downloading psutil-2.2.0.tar.gz (223kB): 223kB downloaded
    Running setup.py (path:/tmp/pip-build-Hqt4sF/psutil/setup.py) egg_info for package psutil
  
      warning: no previously-included files matching '*' found under directory 'docs/_build'
  Downloading/unpacking psycogreen==1.0 (from -r requirements.txt (line 22))
    Downloading psycogreen-1.0.tar.gz
    Running setup.py (path:/tmp/pip-build-Hqt4sF/psycogreen/setup.py) egg_info for package psycogreen
  
  Downloading/unpacking psycopg2==2.5.4 (from -r requirements.txt (line 23))
    Downloading psycopg2-2.5.4.tar.gz (682kB): 682kB downloaded
    Running setup.py (path:/tmp/pip-build-Hqt4sF/psycopg2/setup.py) egg_info for package psycopg2
  
  Requirement already satisfied (use --upgrade to upgrade): pyPdf==1.13 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 24))
  Downloading/unpacking pydot==1.0.2 (from -r requirements.txt (line 25))
    Downloading pydot-1.0.2.tar.gz
    Running setup.py (path:/tmp/pip-build-Hqt4sF/pydot/setup.py) egg_info for package pydot
      Couldn't import dot_parser, loading of dot files will not be possible.
  
  Requirement already satisfied (use --upgrade to upgrade): pyparsing==2.0.3 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 26))
  Requirement already satisfied (use --upgrade to upgrade): pyserial==2.7 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 27))
  Downloading/unpacking python-dateutil==2.4.0 (from -r requirements.txt (line 28))
    Downloading python_dateutil-2.4.0-py2.py3-none-any.whl (175kB): 175kB downloaded
  Downloading/unpacking python-ldap==2.4.19 (from -r requirements.txt (line 29))
    Downloading python-ldap-2.4.19.tar.gz (138kB): 138kB downloaded
    Running setup.py (path:/tmp/pip-build-Hqt4sF/python-ldap/setup.py) egg_info for package python-ldap
      defines: HAVE_SASL HAVE_TLS HAVE_LIBLDAP_R
      extra_compile_args:
      extra_objects:
      include_dirs: /opt/openldap-RE24/include /usr/include/sasl /usr/include
      library_dirs: /opt/openldap-RE24/lib /usr/lib
      libs: ldap_r
  
      file Lib/ldap.py (for module ldap) not found
      file Lib/ldap/controls.py (for module ldap.controls) not found
      file Lib/ldap/extop.py (for module ldap.extop) not found
      file Lib/ldap/schema.py (for module ldap.schema) not found
      warning: no files found matching 'Makefile'
      warning: no files found matching 'Modules/LICENSE'
  Requirement already satisfied (use --upgrade to upgrade): python-openid==2.2.5 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 30))
  Requirement already satisfied (use --upgrade to upgrade): pytz==2014.10 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 31))
  Downloading/unpacking pyusb==1.0.0b2 (from -r requirements.txt (line 32))
    Downloading pyusb-1.0.0b2.tar.gz (57kB): 57kB downloaded
    Running setup.py (path:/tmp/pip-build-Hqt4sF/pyusb/setup.py) egg_info for package pyusb
  
      warning: no files found matching 'ChangeLog'
  Downloading/unpacking qrcode==5.1 (from -r requirements.txt (line 33))
    Downloading qrcode-5.1.tar.gz
    Running setup.py (path:/tmp/pip-build-Hqt4sF/qrcode/setup.py) egg_info for package qrcode
  
  Downloading/unpacking reportlab==3.1.44 (from -r requirements.txt (line 34))
    Downloading reportlab-3.1.44.tar.gz (1.9MB): 1.9MB downloaded
    Running setup.py (path:/tmp/pip-build-Hqt4sF/reportlab/setup.py) egg_info for package reportlab
      ################################################
      #Attempting install of _rl_accel &amp; pyHnj
      #extensions from '/tmp/pip-build-Hqt4sF/reportlab/src/rl_addons/rl_accel'
      ################################################
      ################################################
      #Attempting install of _renderPM
      #extensions from '/tmp/pip-build-Hqt4sF/reportlab/src/rl_addons/renderPM'
      will use package libart 2.3.12
      # installing without freetype no ttf, sorry!
      # You need to install a static library version of the freetype2 software
      # If you need truetype support in renderPM
      # You may need to edit setup.cfg (win32)
      # or edit this file to access the library if it is installed
      ################################################
      Downloading standard T1 font curves
      Finished download of standard T1 font curves
  
      ()
      ########## SUMMARY INFO #########
      ################################################
      #Attempting install of _rl_accel &amp; pyHnj
      #extensions from '/tmp/pip-build-Hqt4sF/reportlab/src/rl_addons/rl_accel'
      ################################################
      ################################################
      #Attempting install of _renderPM
      #extensions from '/tmp/pip-build-Hqt4sF/reportlab/src/rl_addons/renderPM'
      will use package libart 2.3.12
      # installing without freetype no ttf, sorry!
      # You need to install a static library version of the freetype2 software
      # If you need truetype support in renderPM
      # You may need to edit setup.cfg (win32)
      # or edit this file to access the library if it is installed
      ################################################
      Downloading standard T1 font curves
      Finished download of standard T1 font curves
  Downloading/unpacking requests==2.6.0 (from -r requirements.txt (line 35))
    Downloading requests-2.6.0-py2.py3-none-any.whl (469kB): 469kB downloaded
  Requirement already satisfied (use --upgrade to upgrade): six==1.9.0 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 36))
  Downloading/unpacking suds-jurko==0.6 (from -r requirements.txt (line 37))
    Downloading suds-jurko-0.6.tar.bz2 (143kB): 143kB downloaded
    Running setup.py (path:/tmp/pip-build-Hqt4sF/suds-jurko/setup.py) egg_info for package suds-jurko
  
  Requirement already satisfied (use --upgrade to upgrade): vatnumber==1.2 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 38))
  Downloading/unpacking vobject==0.6.6 (from -r requirements.txt (line 39))
    Downloading vobject-0.6.6.tar.gz (53kB): 53kB downloaded
    Running setup.py (path:/tmp/pip-build-Hqt4sF/vobject/setup.py) egg_info for package vobject
  
  Requirement already satisfied (use --upgrade to upgrade): wsgiref==0.1.2 in /usr/lib/python2.7 (from -r requirements.txt (line 40))
  Requirement already satisfied (use --upgrade to upgrade): xlwt==0.7.5 in /usr/lib/python2.7/dist-packages (from -r requirements.txt (line 41))
  Requirement already satisfied (use --upgrade to upgrade): beautifulsoup4 in /usr/lib/python2.7/dist-packages (from ofxparse==0.14-&gt;-r requirements.txt (line 19))
  Requirement already satisfied (use --upgrade to upgrade): setuptools in /usr/lib/python2.7/dist-packages (from pydot==1.0.2-&gt;-r requirements.txt (line 25))
  Requirement already satisfied (use --upgrade to upgrade): pip&gt;=1.4.1 in /usr/lib/python2.7/dist-packages (from reportlab==3.1.44-&gt;-r requirements.txt (line 34))
  Requirement already satisfied (use --upgrade to upgrade): python-stdnum in /usr/lib/python2.7/dist-packages (from vatnumber==1.2-&gt;-r requirements.txt (line 38))
  Installing collected packages: lxml, mock, ofxparse, passlib, psutil, psycogreen, psycopg2, pydot, python-dateutil, python-ldap, pyusb, qrcode, reportlab, requests, suds-jurko, vobject
    Found existing installation: lxml 3.4.4
      Not uninstalling lxml at /usr/lib/python2.7/dist-packages, owned by OS
    Running setup.py install for lxml
      /usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'bugtrack_url'
        warnings.warn(msg)
      Building lxml version 3.4.1.
      Building without Cython.
      ERROR: /bin/sh: 1: xslt-config: not found
  
      ** make sure the development packages of libxml2 and libxslt are installed **
  
      Using build configuration of libxslt
      building 'lxml.etree' extension
      x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -D_FORTIFY_SOURCE=2 -g -fstack-protector-strong -Wformat -Werror=format-security -fPIC -I/tmp/pip-build-Hqt4sF/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
      In file included from src/lxml/lxml.etree.c:239:0:
      /tmp/pip-build-Hqt4sF/lxml/src/lxml/includes/etree_defs.h:14:31: fatal error: libxml/xmlversion.h: No such file or directory
      compilation terminated.
      error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
      Complete output from command /usr/bin/python -c "import setuptools, tokenize;__file__='/tmp/pip-build-Hqt4sF/lxml/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-tUvZhB-record/install-record.txt --single-version-externally-managed --compile:
      /usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'bugtrack_url'
  
    warnings.warn(msg)
  
  Building lxml version 3.4.1.
  
  Building without Cython.
  
  ERROR: /bin/sh: 1: xslt-config: not found
  
  
  
  ** make sure the development packages of libxml2 and libxslt are installed **
  
  
  
  Using build configuration of libxslt
  
  running install
  
  running build
  
  running build_py
  
  creating build
  
  creating build/lib.linux-x86_64-2.7
  
  creating build/lib.linux-x86_64-2.7/lxml
  
  copying src/lxml/doctestcompare.py -&gt; build/lib.linux-x86_64-2.7/lxml
  
  copying src/lxml/builder.py -&gt; build/lib.linux-x86_64-2.7/lxml
  
  copying src/lxml/usedoctest.py -&gt; build/lib.linux-x86_64-2.7/lxml
  
  copying src/lxml/pyclasslookup.py -&gt; build/lib.linux-x86_64-2.7/lxml
  
  copying src/lxml/sax.py -&gt; build/lib.linux-x86_64-2.7/lxml
  
  copying src/lxml/_elementpath.py -&gt; build/lib.linux-x86_64-2.7/lxml
  
  copying src/lxml/ElementInclude.py -&gt; build/lib.linux-x86_64-2.7/lxml
  
  copying src/lxml/__init__.py -&gt; build/lib.linux-x86_64-2.7/lxml
  
  copying src/lxml/cssselect.py -&gt; build/lib.linux-x86_64-2.7/lxml
  
  creating build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/__init__.py -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  creating build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/html5parser.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/diff.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/builder.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/usedoctest.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/_html5builder.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/_setmixin.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/ElementSoup.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/defs.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/_diffcommand.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/clean.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/formfill.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/__init__.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  copying src/lxml/html/soupparser.py -&gt; build/lib.linux-x86_64-2.7/lxml/html
  
  creating build/lib.linux-x86_64-2.7/lxml/isoschematron
  
  copying src/lxml/isoschematron/__init__.py -&gt; build/lib.linux-x86_64-2.7/lxml/isoschematron
  
  copying src/lxml/lxml.etree.h -&gt; build/lib.linux-x86_64-2.7/lxml
  
  copying src/lxml/lxml.etree_api.h -&gt; build/lib.linux-x86_64-2.7/lxml
  
  copying src/lxml/includes/tree.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/xpath.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/c14n.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/dtdvalid.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/xmlparser.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/relaxng.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/config.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/xinclude.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/uri.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/xmlerror.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/etreepublic.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/htmlparser.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/schematron.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/xmlschema.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/xslt.pxd -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/etree_defs.h -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  copying src/lxml/includes/lxml-version.h -&gt; build/lib.linux-x86_64-2.7/lxml/includes
  
  creating build/lib.linux-x86_64-2.7/lxml/isoschematron/resources
  
  creating build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/rng
  
  copying src/lxml/isoschematron/resources/rng/iso-schematron.rng -&gt; build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/rng
  
  creating build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/xsl
  
  copying src/lxml/isoschematron/resources/xsl/RNG2Schtrn.xsl -&gt; build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/xsl
  
  copying src/lxml/isoschematron/resources/xsl/XSD2Schtrn.xsl -&gt; build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/xsl
  
  creating build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
  
  copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_svrl_for_xslt1.xsl -&gt; build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
  
  copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_schematron_skeleton_for_xslt1.xsl -&gt; build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
  
  copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_abstract_expand.xsl -&gt; build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
  
  copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_schematron_message.xsl -&gt; build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
  
  copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_dsdl_include.xsl -&gt; build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
  
  copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/readme.txt -&gt; build/lib.linux-x86_64-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
  
  running build_ext
  
  building 'lxml.etree' extension
  
  creating build/temp.linux-x86_64-2.7
  
  creating build/temp.linux-x86_64-2.7/src
  
  creating build/temp.linux-x86_64-2.7/src/lxml
  
  x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -D_FORTIFY_SOURCE=2 -g -fstack-protector-strong -Wformat -Werror=format-security -fPIC -I/tmp/pip-build-Hqt4sF/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
  
  In file included from src/lxml/lxml.etree.c:239:0:
  
  /tmp/pip-build-Hqt4sF/lxml/src/lxml/includes/etree_defs.h:14:31: fatal error: libxml/xmlversion.h: No such file or directory
  
  compilation terminated.
  
  error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
  
  ----------------------------------------
    Can't roll back lxml; was not uninstalled
  Cleaning up...
  Command /usr/bin/python -c "import setuptools, tokenize;__file__='/tmp/pip-build-Hqt4sF/lxml/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-tUvZhB-record/install-record.txt --single-version-externally-managed --compile failed with error code 1 in /tmp/pip-build-Hqt4sF/lxml
  Storing debug log for failure in /home/aaa/.pip/pip.log
  </code></pre>