Installation on Raspberry Pi 3 fails

[JoergZ2]

Can't install requirments on a Raspberry Pi Model 3 (Buster, actual). This are the errors from pip install:

    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-__djb5k7/lxml/setup.py'"'"'; __file__='"'"'/tmp/pip-install-__djb5k7/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-__djb5k7/lxml/pip-egg-info
         cwd: /tmp/pip-install-__djb5k7/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.

Neither manual installation of libxml2 and libxslt with pip didn't work nor by sudo apt install... After upgrading pip there where some steps futher. Sems that Python or system tries to compile needed libraries. But then it calls for arm-linux-gnueabihf-gcc. This package doesn't exist. Any hints for me?

[pedrinho]

According to https://ofstack.com/python/20751/pythonpip-installation-lxml-error-problem-resolution.html running this solved:

sudo apt-get install python-dev libxml2-dev libxslt1-dev zlib1g-dev

[JoergZ2]

Got again error message:

    arm-linux-gnueabihf-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC -DCYTHON_CLINE_IN_TRACEBACK=0 -I/usr/include/libxml2 -Isrc -Isrc/lxml/includes -I/home/pi/mycroft-core/.venv/include -I/usr/include/python3.7m -c src/lxml/etree.c -o build/temp.linux-armv7l-3.7/src/lxml/etree.o -w
    arm-linux-gnueabihf-gcc: fatal error: Killed signal terminated program cc1
    compilation terminated.
    Compile failed: command 'arm-linux-gnueabihf-gcc' failed with exit status 1
    cc -I/usr/include/libxml2 -I/usr/include/libxml2 -c /tmp/xmlXPathInitza7xouci.c -o tmp/xmlXPathInitza7xouci.o
    /tmp/xmlXPathInitza7xouci.c:2:1: warning: return type defaults to ‘int’ [-Wimplicit-int]
     main (int argc, char **argv) {
     ^~~~
    cc tmp/xmlXPathInitza7xouci.o -lxml2 -o a.out
    error: command 'arm-linux-gnueabihf-gcc' failed with exit status 1
    ----------------------------------------
ERROR: Command errored out with exit status 1: /home/pi/mycroft-core/.venv/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-pj1dk2_9/lxml_553d855c66e04212ac9c767203dc8991/setup.py'"'"'; __file__='"'"'/tmp/pip-install-pj1dk2_9/lxml_553d855c66e04212ac9c767203dc8991/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /tmp/pip-record-i__jdbwd/install-record.txt --single-version-externally-managed --compile --install-headers /home/pi/mycroft-core/.venv/include/site/python3.7/lxml Check the logs for full command output.

Where are the logs that are mentioned in last line? The main problem seems to be missing 'arm-linux-gnueabihf-gcc'