RVM (Ruby Version Manager) is a popular tool that allows developers to easily switch between different Ruby versions and gem sets in their projects. However, sometimes developers might encounter an error like "RVM is not a function" when trying to use the `rvm use` command to select a specific Ruby version. This guide will walk you through the steps to fix this error and ensure you can correctly use RVM to manage your Rubies.
## Table of Contents
- [Understanding the 'RVM is not a function' Error](#understanding-the-rvm-is-not-a-function-error)
- [How to Fix the 'RVM is not a function' Error](#how-to-fix-the-rvm-is-not-a-function-error)
- [Step 1: Check for RVM Installation](#step-1-check-for-rvm-installation)
- [Step 2: Correctly Load RVM in Shell Profile](#step-2-correctly-load-rvm-in-shell-profile)
- [Step 3: Restart Your Terminal](#step-3-restart-your-terminal)
- [FAQ](#faq)
- [Related Links](#related-links)
## Understanding the 'RVM is not a function' Error
The "RVM is not a function" error occurs when the shell cannot find the RVM function to execute the `rvm use` command. This is usually caused by RVM not being correctly loaded in the shell profile or using an incorrect installation method.
## How to Fix the 'RVM is not a function' Error
### Step 1: Check for RVM Installation
First, make sure that RVM is installed on your system by running the following command:
$ rvm -v
If RVM is installed, you should see the current version displayed. If not, follow the [official RVM installation guide](https://rvm.io/rvm/install) to install RVM on your system.
### Step 2: Correctly Load RVM in Shell Profile
Next, ensure that RVM is correctly loaded in your shell profile. Depending on your shell, you may need to modify your `.bashrc`, `.bash_profile`, `.zshrc`, or similar file.
Add the following line to the end of your shell profile file:
```bash
[[ -s "$HOME/.rvm/scripts/rvm" ]] && source "$HOME/.rvm/scripts/rvm"
This line checks for the presence of the RVM script and loads it if found.
Step 3: Restart Your Terminal
After updating your shell profile, close and reopen your terminal or run the following command to reload your shell profile:
$ source ~/.bashrc
Replace .bashrc with the appropriate file for your shell, such as .bash_profile or .zshrc.
Now, you should be able to run the rvm use command without encountering the "RVM is not a function" error.
FAQ
Why am I getting the 'RVM is not a function' error?
This error occurs when the shell cannot find the RVM function to execute the rvm use command, which is usually caused by RVM not being correctly loaded in the shell profile or using an incorrect installation method.
How do I check if RVM is installed on my system?
Run the command rvm -v. If RVM is installed, you should see the current version displayed. If not, follow the official RVM installation guide to install RVM on your system.
What should I do if the error persists after following the steps in this guide?
Ensure that you have the correct shell profile file for your shell, such as .bashrc, .bash_profile, or .zshrc. Also, make sure that the RVM line is at the end of the file.
Can I use RVM with other shell environments besides bash and zsh?
Yes, RVM supports various shells such as bash, zsh, fish, and more. Check the official RVM documentation for details on how to integrate RVM with your preferred shell.
How can I switch to a different Ruby version after fixing the 'RVM is not a function' error?
Use the rvm use command followed by the desired Ruby version, for example:
$ rvm use 2.7.0
This will switch your active Ruby version to the specified version.