- Estoy ejecutando el siguiente comando para instalar los paquetes en ese archivo " - pip install -r requirements.txt --download-cache=~/tmp/pip-cache".
- requisito.txt contiene paquetes como 
# Data formats
# ------------
PIL==1.1.7 # 
html5lib==0.90
httplib2==0.7.4
lxml==2.3.1
# Documentation
# -------------
Sphinx==1.1
docutils==0.8.1
# Testing
# -------
behave==1.1.0
dingus==0.3.2
django-testscenarios==0.7.2
mechanize==0.2.5
mock==0.7.2
testscenarios==0.2
testtools==0.9.14
wsgi_intercept==0.5.1mientras voy a instalar los paquetes "lxml", obtengo el siguiente error
Requirement already satisfied (use --upgrade to upgrade): django-testproject>=0.1.1 in /usr/lib/python2.7/site-packages/django_testproject-0.1.1-py2.7.egg (from django-testscenarios==0.7.2->-r requirements.txt (line 33))
Installing collected packages: lxml, Sphinx, docutils, behave, dingus, mock, testscenarios, testtools, South
  Running setup.py install for lxml
    Building lxml version 2.3.1.
    Building without Cython.
    ERROR: /bin/sh: xslt-config: command not found
    ** make sure the development packages of libxml2 and libxslt are installed **
    Using build configuration of libxslt
    building 'lxml.etree' extension
    gcc -pthread -fno-strict-aliasing -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i686 -mtune=atom -fasynchronous-unwind-tables -D_GNU_SOURCE -fPIC -fwrapv -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i686 -mtune=atom -fasynchronous-unwind-tables -D_GNU_SOURCE -fPIC -fwrapv -fPIC -I/usr/include/python2.7 -c src/lxml/lxml.etree.c -o build/temp.linux-i686-2.7/src/lxml/lxml.etree.o -w
    In file included from src/lxml/lxml.etree.c:239:0:
    src/lxml/etree_defs.h:9:31: fatal error: libxml/xmlversion.h: No such file or directory
    compilation terminated.
    error: command 'gcc' failed with exit status 1
    Complete output from command /usr/bin/python -c "import setuptools;__file__='/root/Projects/ir/build/lxml/setup.py';execfile(__file__)" install --single-version-externally-managed --record /tmp/pip-SwjFm3-record/install-record.txt:
    Building lxml version 2.3.1.
Building without Cython.
ERROR: /bin/sh: xslt-config: command 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
copying src/lxml/cssselect.py -> build/lib.linux-i686-2.7/lxml
copying src/lxml/__init__.py -> build/lib.linux-i686-2.7/lxml
copying src/lxml/sax.py -> build/lib.linux-i686-2.7/lxml
copying src/lxml/pyclasslookup.py -> build/lib.linux-i686-2.7/lxml
copying src/lxml/usedoctest.py -> build/lib.linux-i686-2.7/lxml
copying src/lxml/doctestcompare.py -> build/lib.linux-i686-2.7/lxml
copying src/lxml/_elementpath.py -> build/lib.linux-i686-2.7/lxml
copying src/lxml/ElementInclude.py -> build/lib.linux-i686-2.7/lxml
copying src/lxml/builder.py -> build/lib.linux-i686-2.7/lxml
copying src/lxml/html/clean.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/__init__.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/_dictmixin.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/ElementSoup.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/usedoctest.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/defs.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/builder.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/_html5builder.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/diff.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/html5parser.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/_diffcommand.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/_setmixin.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/soupparser.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/html/formfill.py -> build/lib.linux-i686-2.7/lxml/html
copying src/lxml/isoschematron/__init__.py -> build/lib.linux-i686-2.7/lxml/isoschematron
copying src/lxml/etreepublic.pxd -> build/lib.linux-i686-2.7/lxml
copying src/lxml/tree.pxd -> build/lib.linux-i686-2.7/lxml
copying src/lxml/etree_defs.h -> build/lib.linux-i686-2.7/lxml
copying src/lxml/isoschematron/resources/rng/iso-schematron.rng -> build/lib.linux-i686-2.7/lxml/isoschematron/resources/rng
copying src/lxml/isoschematron/resources/xsl/XSD2Schtrn.xsl -> build/lib.linux-i686-2.7/lxml/isoschematron/resources/xsl
copying src/lxml/isoschematron/resources/xsl/RNG2Schtrn.xsl -> build/lib.linux-i686-2.7/lxml/isoschematron/resources/xsl
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_svrl_for_xslt1.xsl -> build/lib.linux-i686-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_schematron_message.xsl -> build/lib.linux-i686-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_schematron_skeleton_for_xslt1.xsl -> build/lib.linux-i686-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_abstract_expand.xsl -> build/lib.linux-i686-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_dsdl_include.xsl -> build/lib.linux-i686-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/readme.txt -> build/lib.linux-i686-2.7/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
running build_ext
building 'lxml.etree' extension
gcc -pthread -fno-strict-aliasing -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i686 -mtune=atom -fasynchronous-unwind-tables -D_GNU_SOURCE -fPIC -fwrapv -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i686 -mtune=atom -fasynchronous-unwind-tables -D_GNU_SOURCE -fPIC -fwrapv -fPIC -I/usr/include/python2.7 -c src/lxml/lxml.etree.c -o build/temp.linux-i686-2.7/src/lxml/lxml.etree.o -w
In file included from src/lxml/lxml.etree.c:239:0:
src/lxml/etree_defs.h:9:31: fatal error: libxml/xmlversion.h: No such file or directory
compilation terminated.
error: command 'gcc' failed with exit status 1
----------------------------------------
Command /usr/bin/python -c "import setuptools;__file__='/root/Projects/ir/build/lxml/setup.py';execfile(__file__)" install --single-version-externally-managed --record /tmp/pip-SwjFm3-record/install-record.txt failed with error code 1
Storing complete log in /root/.pip/pip.log¿Alguien puede comprobar y orientarme cuál sería el problema y por qué? Falta algún paquete para instalar.
                    
                        python-2.7
                                lxml
                                pip
                                
                    
                    
                        usuario2086641
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sudo ln -s libxml2/libxml libxml.Instale Cython usando
easy_install CythonDespués de completar cython, instale libxslt-devel & libxml2-devel usando
yum install libxslt-devel libxml2-develEsto funcionó para mí.
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sudo yum install libxslt-devel libxml2-devellresuelto para mí, gracias-devembargo, es solo para los paquetes en Raspbian. Instalar cython fue complicado ... Terminé teniendo que usarlosudo pip3 install Cython --install-option="--no-cython-compile"para que funcione correctamente.sudo pip3 install Cythonsolo se estrelló yeasy_install3no hizo nadaLa respuesta seleccionada es correcta, pero solo quería agregar para aquellos que usan Fedora:
libxslt1se llamalibxsltcuando usan dnf. Entonces el comando es:develpara dnf es lo mismo quedevpara apt-get.fuente
sin derechos de sudo puede instalar lxml con:
Como se menciona en la documentación de lxml
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La respuesta certificada funciona perfectamente. Pero simplemente agregando el comando de instalación para que alpine instale libxslt-devel & libxml2-devel
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--updateno es necesario.