then...
... I got the following error:
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
gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/libxml2 -I/root/frappe-bench/env/build/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
gcc: internal compiler error: Killed (program cc1)
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.6/README.Bugs> for instructions.
error: command 'gcc' failed with exit status 4
----------------------------------------
Cleaning up...
Command /root/frappe-bench/env/bin/python2.7 -c "import setuptools, tokenize;__file__=u'/root/frappe-bench/env/build/lxml/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-8X44MY-record/install-record.txt --single-version-externally-managed --compile --install-headers /root/frappe-bench/env/include/site/python2.7 failed with error code 1 in /root/frappe-bench/env/build/lxml
Storing debug log for failure in /root/.pip/pip.log
Traceback (most recent call last):
File "./scripts/virtualenv.py", line 2367, in <module>
main()
File "./scripts/virtualenv.py", line 829, in main
after_install(options, home_dir)
File "./scripts/virtualenv.py", line 2352, in after_install
subprocess.check_output('/'.join([home_dir, 'bin', 'pip install -e frappe/ ']), shell=True)
File "/usr/lib/python2.7/subprocess.py", line 544, in check_output
raise CalledProcessError(retcode, cmd, output=output)
subprocess.CalledProcessError: Command '/root/frappe-bench/env/bin/pip install -e frappe/ ' returned non-zero exit status 1