charm build failing on 18.04

[Raghavendra]

Hi,
  I installed charm using sudo snap install charm --classic on ubuntu 18.04

bu when i try to build my charm using command charm build.I get below error

c/_cffi_backend.c:2:20: fatal error: Python.h: No such file or directory

in log i could see its trying to take includes from snap directory instead of /usr/include

-I/snap/charm/254/usr/include/python3.5m -I/tmp/tmprpjtnvqp/include/python3.5m -c c/_cffi_backend.c -o build/temp.linux-x86_64-3.5/c/_cffi_backend.o

charm version charm 2.4.4