Can't find "Python.h" file while installing Watchman

Usually its the python-dev libs missing. Are you sure the configure uses the python 3 instead of python 2? Because if thats the case you should install python-dev instead of python3-dev.

Same problem if you build watchman under rasbian/raspberry. Install "python-dev".

--

git clone https://github.com/facebook/watchman.git
cd watchman
./autogen.sh
./configure
make

sudo make install

i also did

sudo apt-get install python3-dev

it was still giving me the error then i ran this command

sudo apt-get install python-dev

after that.

make 
sudo make install