Things to install before trying to setup ESP32 tool chain.

Install ESP_ROTS_SDK

Had to install these on fresh installation of Ubuntu 16.04.5 LTS

sudo apt-get update
sudo apt-get install -y git make ncurses-dev flex bison gperf python-pip
sudo pip install pyserial --upgrade

gedit ~/.profile
Add this line to .profile file
export IDF_PATH=~/esp/ESP8266_RTOS_SDK

In the same file edit path to include xtensa toolchain on path
Say toolchain path is $HOME/esp/xtensa-lx106-elf/bin, then PATH should look like:
PATH="$HOME/esp/xtensa-lx106-elf/bin:$HOME/bin:$HOME/.local/bin:$PATH"


Add user to dialout group so that serial port can be opened by ESP scripts
sudo gpasswd --add ${USER} dialout

groups ${USER}
..this will list all the groups you belong to


Changes will be seen on next login.

cd ~/esp/ESP8266_RTOS_SDK/examples/get-started/project_template

******************************
Eclipse Project Settings
https://www.youtube.com/watch?v=H07DjpTtk_k

“C/C++ Build”  Use default build command
python ${IDF_PATH}/tools/windows/eclipse_make.py

"C / C ++ Build" "Environment"
BATCH_BUILD  1
IDF_PATH  C:/msys32/home/Priyank/esp/esp-idf
PATH  C:\msys32\usr\bin;C:\msys32\mingw32\bin;C:\msys32\opt\xtensa-esp32-elf\bin

"C / C ++ General"   "Preprocessor Include Paths, Macros, etc."

CDT GCC Built-in Compiler Settings Cygwin 
xtensa-esp32-elf-gcc ${FLAGS} -E -P -v -dD "${INPUTS}"

CDT GCC Build Output Parser 
xtensa-esp32-elf-((g?cc)|([gc]\+\+)|(clang))