From 7cd19faf697dd34ef9e2ff0086739b9e86a9781b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcus=20Sch=C3=A4fer?= <marcus.schaefer@gmail.com>
Date: Mon, 19 Oct 2026 21:23:11 +0200
Subject: [PATCH 1/2] Use the which crate

Use the which crate to lookup a binary in PATH
---
 common/src/lookup.rs | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/common/src/lookup.rs b/common/src/lookup.rs
index 8ceea6f3..0d2cefed 100644
--- a/common/src/lookup.rs
+++ b/common/src/lookup.rs
@@ -23,7 +23,6 @@
 //
 use std::collections::HashMap;
 use std::env;
-use std::fs;
 
 use crate::flakelog::FlakeLog;
 
@@ -137,14 +136,11 @@ impl Lookup {
     }
 
     pub fn which(command: &str) -> bool {
-        if let Ok(path) = env::var("PATH") {
-            for path_entry in path.split(':') {
-                let abs_command = format!("{path_entry}/{command}");
-                if fs::metadata(abs_command).is_ok() {
-                    return true;
-                }
-            }
-        }
-        false
+        /*!
+        Check if the given command can be called. A command given
+        without a path is searched in $PATH the same way it is
+        found when it gets called. Only executable files count
+        !*/
+        which::which(command).is_ok()
     }
 }

From f97f2d82007e52f05e38265add869d3a307ab083 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcus=20Sch=C3=A4fer?= <marcus.schaefer@gmail.com>
Date: Mon, 19 Oct 2026 21:23:58 +0200
Subject: [PATCH 2/2] Fix bwrap lookup in bubblewrwap-pilot

bubblewrap-pilot checks that bwrap exists by searching PATH,
but it then runs bwrap from the fixed path /usr/bin/bwrap.
As such the search doesn't make any sense. This commit
Fixes #174
---
 bubblewrap-pilot/src/bubblewrap.rs | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/bubblewrap-pilot/src/bubblewrap.rs b/bubblewrap-pilot/src/bubblewrap.rs
index 60bf2ab5..d960fcf0 100644
--- a/bubblewrap-pilot/src/bubblewrap.rs
+++ b/bubblewrap-pilot/src/bubblewrap.rs
@@ -37,7 +37,7 @@ use uzers::get_current_username;
 
 use std::env;
 use std::fs;
-use std::io::Write;
+use std::io::{self, Write};
 use std::path::Path;
 use std::process::{Command, ExitCode};
 
@@ -93,17 +93,6 @@ pub fn create(program_name: &str) -> Result<String, FlakeError> {
     name of the meta data file which represents the instance is
     returned by this method
     !*/
-    // The sandbox is created by the bwrap program
-    if ! Lookup::which(defaults::BWRAP) {
-        return Err(FlakeError::IOError {
-            kind: "Sandbox engine not found".to_string(),
-            message: format!(
-                "{} is required to run this flake, please install it",
-                defaults::BWRAP
-            )
-        })
-    }
-
     // A sandbox provides no entry point like a container image
     // does. The command to call in it has to be known
     if get_target_app_path(program_name) == "/" {
@@ -251,7 +240,20 @@ fn run_sandbox(
     if spawned.is_err() {
         delete_sandbox_id_file(sandbox_id_file);
     }
-    let mut child = spawned?;
+    let mut child = match spawned {
+        Ok(child) => child,
+        // The sandbox is created by the bwrap program
+        Err(error) if error.kind() == io::ErrorKind::NotFound => {
+            return Err(FlakeError::IOError {
+                kind: "Sandbox engine not found".to_string(),
+                message: format!(
+                    "{} is required to run this flake, please install it",
+                    defaults::BWRAP_PATH
+                )
+            })
+        },
+        Err(error) => return Err(error.into())
+    };
 
     let pid = child.id();
     if Lookup::is_debug() {