[OpenR] The OpenR install script does not work on Ubuntu 20.04

[jadinm]

The OpenR install script does not work on Ubuntu 20.04.

Though it was not sufficient, the first steps to debug it is to remove python2 dependencies and update gcc version:

diff --git a/ipmininet/install/build_openr-rc-20190419-11514.sh b/ipmininet/install/build_openr-rc-20190419-11514.sh
index 3823a67..b1f3264 100755
--- a/ipmininet/install/build_openr-rc-20190419-11514.sh
+++ b/ipmininet/install/build_openr-rc-20190419-11514.sh
@@ -3,9 +3,9 @@
 set -exo pipefail
 ### Install packages for Debian-based OS ###
 
-apt-get update && apt-get install -yq autoconf-archive bison build-essential cmake curl flex git gperf joe libboost-all-dev libcap-dev libdouble-conversion-dev libevent-dev libgflags-dev libgoogle-glog-dev libkrb5-dev libpcre3-dev libpthread-stubs0-dev libnuma-dev libsasl2-dev libsnappy-dev libsqlite3-dev libssl-dev libtool netcat-openbsd pkg-config sudo unzip wget python3-venv python-setuptools python3-setuptools python-pip python3-pip ccache
-apt-get install -yq gcc-'5' g++-'5'
-update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-'5' 40 --slave /usr/bin/g++ g++ /usr/bin/g++-'5'
+apt-get update && apt-get install -yq autoconf-archive bison build-essential cmake curl flex git gperf joe libboost-all-dev libcap-dev libdouble-conversion-dev libevent-dev libgflags-dev libgoogle-glog-dev libkrb5-dev libpcre3-dev libpthread-stubs0-dev libnuma-dev libsasl2-dev libsnappy-dev libsqlite3-dev libssl-dev libtool netcat-openbsd pkg-config sudo unzip wget python3-venv python3-setuptools python3-pip ccache
+apt-get install -yq gcc-'7' g++-'7'
+update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-'7' 40 --slave /usr/bin/g++ g++ /usr/bin/g++-'7'
 update-alternatives --config gcc
 
 FOLLY_REV="3ceffd7d145be3c85a2aae39f99eb86ea730bdcc"

fizz still cannot be compiled.