feat(init): Use which-rs to resolve starship path

This patch uses the which crate to resolve the starship path, replacing the
current_exe() mechanism.

Co-authored-by: Kevin Song <[email protected]>
Co-authored-by: David Knaack <[email protected]>
Co-authored-by: Dario Vladović <[email protected]>

src/init/mod.rs

@@ -3,6 +3,8 @@ use std::ffi::OsStr;
 use std::path::{Path, PathBuf};
 use std::{env, io};
 
+use which::which;
+
 /* We use a two-phase init here: the first phase gives a simple command to the
 shell. This command evaluates a more complicated script using `source` and
 process substitution.
@@ -23,9 +25,11 @@ struct StarshipPath {
 }
 impl StarshipPath {
     fn init() -> io::Result<Self> {
-        Ok(Self {
-            native_path: env::current_exe()?,
-        })
+        let exe_name = option_env!("CARGO_PKG_NAME").unwrap_or("starship");
+
+        let native_path = which(exe_name).or_else(|_| env::current_exe())?;
+
+        Ok(Self { native_path })
     }
     fn str_path(&self) -> io::Result<&str> {
         let current_exe = self