I recently updated to MacOS Catalina. And faced some issues when running some git and npm commands.

I cloned a repo from GitHub and tried to run

npm ci

This error appeared after running the command

No Xcode or CLT version detected

as the cover image above shows.

Now as every faithful developer, I googled the error and pointed me to StackOverflow and some other blogs.

I checked CommandLineTools path with

xcode-select -print-path

and it showed the correct path

/Library/Developer/CommandLineTools

So maybe the package was broken or some links were not created (not sure lol). So I deleted it

sudo rm -rf /Library/Developer/CommandLineTools

After deleting CommandLineTools this window prompted me

If the window didn't show, just run

xcode-select --install

But for some reason it didn't download and showed me an error

So I went to download it manually in Apple website. Use your Apple ID to sign in.
https://developer.apple.com/download/more/?=Command%20Line%20Tools

I chose the latest one which is the first entry in the table.

After downloading I just installed the package normally:

And everything worked back to normal after that.

Hope this helps out somebody.

Cheers!