Q:

How do I install required gcc and libc6-dev files on 20.04?

I am trying to build software from source (specifically, Asymptote 2.66).
This worked fine on Ubuntu 18.04.
But a number of the files the make file needs, such as:

byteswap-16.h and libio.h in /usr/include/x86-64-linux-gnu/bits/
limits.h in /usr/lib/gcc/x86-64-linux-gnu/7/include-fixed

are simply not present in Ubuntu 20.04. Well, not present in the expected locations. They can be found in /snap/gnome-3-34-1804.
Every bit of help online says to install build-essentials, libc6-dev, and linux-libc-dev.
But all of these are installed. Other than manually copying needed files one by one, is there a way to get all the necessary files to build from source?

A:

At first - the Asymptote 2.62 is contained in the official repository, so you can start getting its build-dependencies by enabling source code repositories in Software & Updates (software-properties-gtk) and by using the following command:
sudo apt-get build-dep asymptote

And then compile the source code:
cd ~/Downloads
wget https://github.com/vectorgraphics/asymptote/archive/2.66.tar.gz
tar -xf 2.66.tar.gz
cd asymptote-2.66
./autogen.sh
./configure
make
sudo make install

and then run the application with asy command.

