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# Building wheels and fs_util will be skipped. Delete if not intended.
[ci skip-build-wheels]

src/rust/engine/process_execution/src/nailgun/nailgun_pool.rs

@@ -2,7 +2,7 @@
 // Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 use std::io::{self, BufRead, Read};
-use std::net::SocketAddr;
+use std::net::{IpAddr, Ipv4Addr, SocketAddr};
 use std::os::unix::process::ExitStatusExt;
 use std::path::{Path, PathBuf};
 use std::process::Stdio;
@@ -30,7 +30,7 @@ struct PoolEntry {
   process: Arc<Mutex<NailgunProcess>>,
 }
 
-pub type Port = usize;
+pub type Port = u16;
 
 ///
 /// A NailgunPool contains a small Vec of running NailgunProcess instances, fingerprinted with the
@@ -365,7 +365,7 @@ impl BorrowedNailgunProcess {
 
   pub fn address(&self) -> SocketAddr {
     let port = self.0.as_ref().unwrap().port;
-    format!("127.0.0.1:{:?}", port).parse().unwrap()
+    SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), port)
   }
 
   pub fn workdir_path(&self) -> &Path {

src/rust/engine/process_executor/src/main.rs

@@ -186,8 +186,8 @@ struct Opt {
   #[structopt(long, default_value = "128")]
   cache_rpc_concurrency: usize,
 
-  /// If set, use run the process through a Nailgun server.
-  /// This will likely start a new Nailgun server as a side effect.
+  /// If set, run the process through a Nailgun server with the given digest.
+  /// This will start a new Nailgun server as a side effect, but will tear it down on exit.
   #[structopt(long)]
   use_nailgun_digest: Option<Fingerprint>,