Install Watchman (by Facebook) on Ubuntu 19.04 and 20.04

Updated in Aug 2020

Ubuntu 19.04 and Watchman

Step 1: Clone the Watchman repository and checkout the right branch

$ cd ~
$ git clone https://github.com/facebook/watchman.git
$ cd watchman/
$ git checkout v4.9.0

Step 2: Download the pre-requisites

$ sudo apt install -y autoconf automake build-essential python-dev

Step 3: Run the scripts

$ ./autogen.sh 

If this throws errors like: your system lacks libtoolize

$ sudo apt install libtool
$ ./autogen.sh

$ ./configure

If you cannot find the script configure, you might want to run./autogen.sh again after installing the libtool package

If you still cannot find the configure script, even after running autogen.sh again, and get an error saying: pkg-config appears to be missing (not available to autoconf tools)

$ sudo apt install pkg-config
$ ./autogen.sh
$ ./configure.sh

Step 4: Build Executables

$ make

If this throws an error like: fatal error: openssl/sha.h: No such file or directory

$ sudo apt install libtool

If it throws an error like: Makefile:4446: scm/watchman-Mercurial.o] Error 1

$ ./configure --without-python --without-pcre --enable-lenient
$ make 

Step 5: Install

$ sudo make install

Step 6: Verify

$ watchman --version