Linux build instructions problems

I had a couple of issues using the build instructions for Linux with Ubuntu 20.04.1 LTS. Here is a list of the issues and what I did to workaround the them.

The line:
curl -sL https://deb.nodesource.com/setup_8.x | sudo -E bash -

Issue:
Fails to install. There is a depreciation warning and it says that the particular distribution that I am using (Codename: focal) is not supported.

Workaround:
sudo apt-get install npm

Fixed the issue for me but may have installed more than was necessary if only a specific component was required.

The line:
mono app/main-process/ink/inklecate_win.exe

Issue:
Exits and returns the error: Cannot open assembly 'app/main-process/iCannot open assembly 'app/main-process/ink/inklecate_win.exe': File does not contain a valid CIL image.nk/inklecate_win.exe': File does not contain a valid CIL image.

Workaround:
I skipped it and ran the ./INSTALL command instead and everything worked fine. Inky opens and appears to be running properly as well.

Start with the Linux build instructions and reproduce the reported commands on Ubuntu 20.04.1 LTS, including the NodeSource setup command, the mono command for app/main-process/ink/inklecate_win.exe, and ./INSTALL. Done means the instructions use working steps and a clean installation succeeds without the reported assembly error.

Written by the indexing model from the issue text.