scipy: Unable to compile scipy 1.4

I am unable to compile scipy 1.4 on Ubuntu 18.04 LTS with python3.6 and I tried both with python3.6 -m pip install . and python3.6 setup.py install,

I want to point out that I have installed pybind11 as recently as today and that still does not resolve the issue. Where am I going wrong ? This has never happened before.

`creating /tmp/tmpespaluwr/tmp creating /tmp/tmpespaluwr/tmp/tmpespaluwr compile options: ‘-I/usr/include/python3.6m -c’ extra options: ‘-std=c++14 -fvisibility=hidden’ x86_64-linux-gnu-g++: /tmp/tmpespaluwr/main.c C compiler: x86_64-linux-gnu-g++ -pthread -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC

creating /tmp/tmpnxdut7p6/tmp creating /tmp/tmpnxdut7p6/tmp/tmpnxdut7p6 compile options: ‘-I/usr/include/python3.6m -c’ x86_64-linux-gnu-g++: /tmp/tmpnxdut7p6/main.c building ‘scipy.fft._pocketfft.pypocketfft’ extension compiling C++ sources C compiler: x86_64-linux-gnu-g++ -pthread -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC

compile options: ‘-DPOCKETFFT_PTHREADS -I/root/.local/include/python3.6m -I/usr/local/include/python3.6 -I/usr/local/lib/python3.6/dist-packages/numpy/core/include -I/usr/include/python3.6m -c’ extra options: ‘-std=c++14 -fvisibility=hidden’ x86_64-linux-gnu-g++: scipy/fft/_pocketfft/pypocketfft.cxx scipy/fft/_pocketfft/pypocketfft.cxx:15:10: fatal error: pybind11/pybind11.h: No such file or directory #include <pybind11/pybind11.h> ^~~~~~~~~~~~~~~~~~~~~ compilation terminated. Running from scipy source directory. /usr/local/lib/python3.6/dist-packages/numpy/distutils/system_info.py:782: UserWarning: Specified path /usr/local/include/python3.6m is invalid. return self.get_paths(self.section, key) error: Command “x86_64-linux-gnu-g++ -pthread -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC -DPOCKETFFT_PTHREADS -I/root/.local/include/python3.6m -I/usr/local/include/python3.6 -I/usr/local/lib/python3.6/dist-packages/numpy/core/include -I/usr/include/python3.6m -c scipy/fft/_pocketfft/pypocketfft.cxx -o build/temp.linux-x86_64-3.6/scipy/fft/_pocketfft/pypocketfft.o -MMD -MF build/temp.linux-x86_64-3.6/scipy/fft/_pocketfft/pypocketfft.o.d -std=c++14 -fvisibility=hidden” failed with exit status 1 `