Try to find rustfmt in more places

Cargo.lock

@@ -1395,6 +1395,7 @@ dependencies = [
  "ra_project_model",
  "ra_syntax",
  "ra_text_edit",
+ "ra_toolchain",
  "ra_tt",
  "rand",
  "rustc-hash",

crates/ra_toolchain/src/lib.rs

@@ -15,6 +15,10 @@ pub fn rustup() -> PathBuf {
     get_path_for_executable("rustup")
 }
 
+pub fn rustfmt() -> PathBuf {
+    get_path_for_executable("rustfmt")
+}
+
 /// Return a `PathBuf` to use for the given executable.
 ///
 /// E.g., `get_path_for_executable("cargo")` may return just `cargo` if that

crates/rust-analyzer/Cargo.toml

@@ -41,6 +41,7 @@ ra_text_edit = { path = "../ra_text_edit" }
 vfs = { path = "../vfs" }
 vfs-notify = { path = "../vfs-notify" }
 ra_cfg = { path = "../ra_cfg"}
+ra_toolchain = { path = "../ra_toolchain" }
 
 # This should only be used in CLI
 ra_db = { path = "../ra_db" }

crates/rust-analyzer/src/handlers.rs

@@ -650,7 +650,7 @@ pub(crate) fn handle_formatting(
 
     let mut rustfmt = match &snap.config.rustfmt {
         RustfmtConfig::Rustfmt { extra_args } => {
-            let mut cmd = process::Command::new("rustfmt");
+            let mut cmd = process::Command::new(ra_toolchain::rustfmt());
             cmd.args(extra_args);
             if let Some(&crate_id) = crate_ids.first() {
                 // Assume all crates are in the same edition