I have an error: command 'clang++-3.9' failed: No such file or directory

[Robocop01]

Good Day!

I have an error: command 'clang++-3.9' failed: No such file or directory
What is a problem? Help me please.
clang++-3.9 -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O3 -Wall -fPIC -I/usr/local/include/python3.9 -c src/mapnik_color.cpp -o build/temp.linux-x86_64-3.9/src/mapnik_color.o -I/home/admin/python-mapnik/mason_packages/.link/include -I/home/admin/python-mapnik/mason_packages/.link/include/mapnik/agg -I/home/admin/python-mapnik/mason_packages/.link/include/mapnik -I./mason_packages/.link/include -I./mason_packages/.link/include/freetype2 -I./mason_packages/.link/include/libpng16 -I./mason_packages/linux-x86_64/libgdal/2.1.3/include -I./mason_packages/.link/include/cairo -I./mason_packages/.link/include/pixman-1 -DMAPNIK_MEMORY_MAPPED_FILE -DMAPNIK_HAS_DLCFN -DBIGINT -DBOOST_REGEX_HAS_ICU -DHAVE_JPEG -DMAPNIK_USE_PROJ4 -DHAVE_PNG -DHAVE_WEBP -DHAVE_TIFF -DLINUX -DMAPNIK_THREADSAFE -DMAPNIK_NO_ATEXIT -DBOOST_SPIRIT_NO_PREDEFINED_TERMINALS=1 -DBOOST_PHOENIX_NO_PREDEFINED_TERMINALS=1 -DBOOST_SPIRIT_USE_PHOENIX_V3=1 -DNDEBUG -DHAVE_CAIRO -DGRID_RENDERER -DSVG_RENDERER -std=c++11 -fPIC -std=c++11 -D_GLIBCXX_USE_CXX11_ABI=0 -fvisibility-inlines-hidden -Wall -pthread -ftemplate-depth-300 -Wsign-compare -Wshadow -O3 error: command 'clang++-3.9' failed: No such file or directory
It is my Dockerfile
`FROM python:3.9.7

python-setuptools

RUN apt-get update \

&& apt-get install -y --no-install-recommends apt-utils \

&& apt-get install unixodbc-dev -y
&& apt-get install python2.7-dev -y
&& apt-get install libboost-python-dev libboost-thread-dev libboost-system-dev -y
&& chmod -R 777 /usr/local/lib/python3.9
&& apt-get install clang-3.9 -y
&& adduser admin --gecos '' --disabled-login
USER admin
WORKDIR /home/admin

COPY --chown=admin:admin requirements.txt ./
ENV PATH="/home/admin/.local/bin:${PATH}"
RUN pip install --user --no-cache-dir -r requirements.txt

RUN git clone https://github.com/mapnik/python-mapnik.git -b v3.0.x
&& cd python-mapnik
&& export BOOST_SYSTEM_LIB=boost_system && export BOOST_THREAD_LIB=boost_thread
&& python setup.py develop install

#RUN python setup.py test`