Use which crate to resolve binary paths on agent (#120)

* Use which crate to resolve binary paths on agent

* Cargo fmt

crates/bh_agent_server/Cargo.toml

@@ -17,6 +17,7 @@ env_logger = { version = "0.11.2", default-features = false, features = ["auto-c
 bimap = "0.6.3"
 argh = "0.1.12"
 unicode_reader = "1.0.2"
+which = "6.0.0"
 
 [target.'cfg(target_family = "unix")'.dependencies]
 daemonize = "0.5.0"

crates/bh_agent_server/src/state.rs

@@ -1,13 +1,14 @@
 use bimap::BiMap;
 use log::{debug, trace};
 use std::collections::HashMap;
-use std::ffi::OsStr;
+use std::ffi::OsString;
 use std::fs::{File, OpenOptions};
 use std::sync::{Arc, RwLock};
 use std::thread::sleep;
 use std::time::Duration;
 
 use subprocess::{Popen, PopenConfig};
+use which::which;
 
 use bh_agent_common::AgentError::{
     InvalidFileDescriptor, InvalidProcessId, IoError, ProcessStartFailure, Unknown,
@@ -127,7 +128,10 @@ impl BhAgentState {
                 Redirection::Save => subprocess::Redirection::Pipe,
             },
             detached: false,
-            executable: config.executable.map(|s| s.into()),
+            executable: config
+                .executable
+                .and_then(|s| which(&s).ok())
+                .map(|s| s.into()),
             env: config.env.map(|v| {
                 v.iter()
                     .map(|t| (t.0.clone().into(), t.1.clone().into()))
@@ -143,16 +147,14 @@ impl BhAgentState {
             popenconfig.setpgid = config.setpgid || popenconfig.setpgid;
         }
 
-        let proc = Popen::create(
-            config
-                .argv
-                .iter()
-                .map(OsStr::new)
-                .collect::<Vec<_>>()
-                .as_slice(),
-            popenconfig,
-        )
-        .map_err(|e| ProcessStartFailure(e.to_string()))?;
+        let mut argv: Vec<OsString> = config.argv.iter().map(OsString::from).collect();
+        if !argv.is_empty() {
+            argv[0] = which(&argv[0])
+                .map_err(|e| ProcessStartFailure(e.to_string()))?
+                .into_os_string();
+        }
+        let proc =
+            Popen::create(&argv, popenconfig).map_err(|e| ProcessStartFailure(e.to_string()))?;
 
         let proc_id = self.take_proc_id()?;
 

python/binharness/bootstrap/subprocess.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import os
 import subprocess
 import time
 from typing import TYPE_CHECKING
@@ -30,8 +31,7 @@ def __init__(
         """Create an AgentConnection."""
         process = subprocess.Popen(
             [str(agent_binary), address, str(port)],
-            stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE,
+            env={**os.environ, "RUST_LOG": "bh_agent_server::util::read_chars=trace"},
         )
         self._process = process
         time.sleep(0.1)