gcc: error trying to exec 'cc1plus': execvp: No such file or directory

i am trying to run the ovs faucet tutorial. One of steps is to compile the faucet container package. I am getting the following error when I tried to run it

gcc: error trying to exec 'cc1plus': execvp: No such file or directory

I am on Ubuntu 18.04, kernel version 5.4.0-65-generic

I made sure that my gcc and g++ are up to date.
when i tried sudo apt-get install g++(gcc), it tells me i already have the latest version for both.

$ sudo apt-get install g++
Reading package lists... Done
Building dependency tree       
Reading state information... Done
g++ is already the newest version (4:7.4.0-1ubuntu2.3).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

$ gcc --version
gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ g++ --version
g++ (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
Copyright (C) 2017 Free Software Foundation, Inc.

$ g++ --print-prog-name=cc1plus
/usr/lib/gcc/x86_64-linux-gnu/7/cc1plus

This failed when comipiling the first cpp file. It appears to compile the c file before the error.

If anyone can give me some pointers, that’d be appreciated it.