I'm not reviewing the source code to ripgrep, and even if I did, I'm definately not review the code of all of it's dependancies, which are getting downloaded when I build it anyway.
Also, it's not objectively easier to make a mistake when you type one command, than when you type three. I would say my error rate goes up as I type more, so I feel it's objectively easier to make a mistake with your method.
Also, why not have cargo install stuff? It already does. If it makes ten thousand's people lives easier, by letting them type one line instead of three, and have to go find the right git repository to clone, then surely that's better?
Also, you still haven't discussed that your method does the (in my opinion) clearly wrong thing of building whatever the current state of the master branch is, rather than a release.