Error Fix: RVM is not a function, selecting rubies with 'rvm use ...' will not work.

When running the command you will get:

// ♥ rvm use 2.7.0 --default

RVM is not a function, selecting rubies with 'rvm use ...' will not work.

You need to change your terminal emulator preferences to allow login shell.
Sometimes it is required to use /bin/bash --login as the command.
Please visit https://rvm.io/integration/gnome-terminal/ for an example.

To permanently fix the second error:

Add this into your VSCode settings.json file:

// Linux
"terminal.integrated.shellArgs.linux": ["-l"]

Source for the permanent fix: https://code.visualstudio.com/docs/editor/integrated-terminal