7. Running Tools

This chapter describes how to run specific tools using CriticalUp.

The examples in this chapter assume the following directory structure:

└── project
   └── criticalup.toml

After installing CriticalUp, authenticating, and installing a toolchain, CriticalUp can be used to run the specified tools from the installed toolchain.

CriticalUp creates a set of binary proxies for tools which it has installed. Which discover the relevant criticalup.toml and executes the correct version of the tool.


If CriticalUp does not find a criticalup.toml in the current directory, it will search the parent directory, then the parent of that, up to the root directory of the system.

cd project
criticalup run rustc --help

7.1. Locating Tools

We can find the true path of a tool for the current toolchain with the which command:

cd project
criticalup which rustc