tar -zxvf matplotlib-3.1.2.tar.gzcd matplotlib-3.1.2python setup.py build

BUILDING MATPLOTLIB  matplotlib: yes [3.1.2]      python: yes [3.6.3 (default, Nov 23 2020, 09:56:24)  [GCC 4.8.5 20150623                  (Red Hat 4.8.5-44)]]    platform: yes [linux]OPTIONAL SUBPACKAGES sample_data: yes [installing]       tests: no  [skipping due to configuration]OPTIONAL BACKEND EXTENSIONS         agg: yes [installing]       tkagg: yes [installing; run-time loading from Python Tcl/Tk]      macosx: no  [Mac OS-X only]OPTIONAL PACKAGE DATA        dlls: no  [skipping due to configuration]/usr/local/python3.6/lib/python3.6/distutils/dist.py:261: UserWarning: Unknown distribution option: 'project_urls'  warnings.warn(msg)running buildrunning build_pycopying lib/matplotlib/mpl-data/matplotlibrc -> build/lib.linux-aarch64-3.6/matplotlib/mpl-dataUPDATING build/lib.linux-aarch64-3.6/matplotlib/_version.pyset build/lib.linux-aarch64-3.6/matplotlib/_version.py to '3.1.2'running build_extbuilding 'matplotlib._png' extensiongcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -fPIC -DPY_ARRAY_UNIQUE_SYMBOL=MPL_matplotlib__png_ARRAY_API -DNPY_NO_DEPRECATED_API=NPY_1_7_API_VERSION -D__STDC_FORMAT_MACROS=1 -I/home/wah/venv/lib/python3.6/site-packages/numpy/core/include -I/home/wah/venv/include -I/usr/local/python3.6/include/python3.6m -c src/checkdep_libpng.c -o build/temp.linux-aarch64-3.6/src/checkdep_libpng.o -I/usr/include/libpng15src/checkdep_libpng.c:2:9: note: #pragma message: Compiling with libpng version 1.5.13. #pragma message("Compiling with libpng version " PNG_LIBPNG_VER_STRING ".")         ^gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -fPIC -DPY_ARRAY_UNIQUE_SYMBOL=MPL_matplotlib__png_ARRAY_API -DNPY_NO_DEPRECATED_API=NPY_1_7_API_VERSION -D__STDC_FORMAT_MACROS=1 -I/home/wah/venv/lib/python3.6/site-packages/numpy/core/include -I/home/wah/venv/include -I/usr/local/python3.6/include/python3.6m -c src/_png.cpp -o build/temp.linux-aarch64-3.6/src/_png.o -I/usr/include/libpng15gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -fPIC -DPY_ARRAY_UNIQUE_SYMBOL=MPL_matplotlib__png_ARRAY_API -DNPY_NO_DEPRECATED_API=NPY_1_7_API_VERSION -D__STDC_FORMAT_MACROS=1 -I/home/wah/venv/lib/python3.6/site-packages/numpy/core/include -I/home/wah/venv/include -I/usr/local/python3.6/include/python3.6m -c src/mplutils.cpp -o build/temp.linux-aarch64-3.6/src/mplutils.o -I/usr/include/libpng15g++ -pthread -shared build/temp.linux-aarch64-3.6/src/checkdep_libpng.o build/temp.linux-aarch64-3.6/src/_png.o build/temp.linux-aarch64-3.6/src/mplutils.o -L/usr/local/python3.6/lib -lpython3.6m -o build/lib.linux-aarch64-3.6/matplotlib/_png.cpython-36m-aarch64-linux-gnu.so -lpng15collect2: error: ld terminated with signal 9 [Killed]error: command 'g++' failed with exit status 1