Add --locked

Author: mo8it

README.md

@@ -74,13 +74,13 @@ If you get a permission denied message, you might have to exclude the directory
 
 ## Manually
 
-Basically: Clone the repository at the latest tag, run `cargo install --path .`.
+Basically: Clone the repository at the latest tag, run `cargo install --locked --path .`.
 
 ```bash
 # find out the latest version at https://github.com/rust-lang/rustlings/releases/latest (on edit 5.6.1)
 git clone -b 5.6.1 --depth 1 https://github.com/rust-lang/rustlings
 cd rustlings
-cargo install --force --path .
+cargo install --locked --force --path .
 ```
 
 If there are installation errors, ensure that your toolchain is up to date. For the latest, run:

install.ps1

@@ -78,7 +78,7 @@ Set-Location $path
 git checkout -q tags/$version
 
 Write-Host "Installing the 'rustlings' executable..."
-cargo install --force --path .
+cargo install --locked --force --path .
 if (!(Get-Command rustlings -ErrorAction SilentlyContinue)) {
     Write-Host "WARNING: Please check that you have '~/.cargo/bin' in your PATH environment variable!"
 }

install.sh

@@ -165,7 +165,7 @@ echo "Checking out version $Version..."
 git checkout -q ${Version}
 
 echo "Installing the 'rustlings' executable..."
-cargo install --force --path .
+cargo install --locked --force --path .
 
 if ! [ -x "$(command -v rustlings)" ]
 then