Function cache_root 

pub fn cache_root(bin: &'static str) -> Result<PathBuf>

Available on crate feature config only.

Returns the path to the user’s cache directory for the given binary.

This is determined by the following steps:

• If the environment variable <BIN>_CACHE_DIR is set, return that.
• If the operating environment provides a cache directory, return $CACHE_DIR/<bin>.
• Otherwise, return an error.

The default directories are as follows:

Platform	Value	Example
Linux	$XDG_CACHE_HOME/iroh or $HOME/.cache/iroh	/home/.cache/iroh
macOS	$HOME/Library/Caches/iroh	/Users/Alice/Library/Caches/iroh
Windows	{FOLDERID_LocalAppData}/iroh	C:\Users\Alice\AppData\Roaming\iroh