Trying to Install c-lightning

In my work with walletscrutiny.com, I had to test an app called Spark Wallet. The app needs a c-lightning node, which means installing c-lightning.

Several issues cropped up. 

One, the instructions given here, are for Ubuntu, and not for Linux Mint, which is the machine I'm trying this. 

Issue 1: 

sudo add-apt-repository -u ppa:lightningnetwork/ppa

does not work. No such option as -u

I removed the -u and it worked.

Issue 2:

gpg: keyserver receive failed: General error

Which I fixed by changing line 216 of mintSources.py 

Issue 3:

Package 'snapd' has no installation candidate

Fixed by moving a file that causes the restriction, which enabled snap.

2021-11-24 Installing Bitcoin-Core