Installing Error

[EspElement]

I keep getting this error when trying to install. I tried flashing the core a few times but still keep getting this error. I do have libxml2 and libxslt installed... I do not understand what I need to do...

Thanks!!!

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ERROR: Command errored out with exit status 1:
command: /home/pi/mycroft-core/.venv/bin/python -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-q1yub_wl/lxml/setup.py'"'"'; file='"'"'/tmp/pip-install-q1yub_wl/lxml/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(file);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, file, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-install-q1yub_wl/lxml/pip-egg-info
cwd: /tmp/pip-install-q1yub_wl/lxml/
Complete output (3 lines):
Building lxml version 4.6.2.
Building without Cython.
Error: Please make sure the libxml2 and libxslt development packages are installed.
----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
WARNING: You are using pip version 20.0.2; however, version 20.3.3 is available.
You should consider upgrading via the '/home/pi/mycroft-core/.venv/bin/python -m pip install --upgrade pip' command.