Ensure passing relative paths to CLI works

src/main.rs

@@ -1,5 +1,5 @@
 use std::ffi::{OsStr, OsString};
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::process;
 
 use clap::Parser;
@@ -67,8 +67,16 @@ fn main() {
         mode,
         hardened: args.hardened,
         no_net: args.no_net,
-        extra_rw: args.extra_rw,
-        extra_ro: args.extra_ro,
+        extra_rw: args
+            .extra_rw
+            .iter()
+            .map(|p| canonicalize_or_exit(p))
+            .collect(),
+        extra_ro: args
+            .extra_ro
+            .iter()
+            .map(|p| canonicalize_or_exit(p))
+            .collect(),
         command,
         command_args,
         chdir,
@@ -104,7 +112,7 @@ fn assert_binary_exists(name: &OsStr) -> PathBuf {
 
 fn assert_chdir(explicit: Option<PathBuf>) -> PathBuf {
     if let Some(p) = explicit {
-        return p;
+        return canonicalize_or_exit(&p);
     }
     match std::env::current_dir() {
         Ok(p) => p,
@@ -118,6 +126,13 @@ fn assert_chdir(explicit: Option<PathBuf>) -> PathBuf {
     }
 }
 
+fn canonicalize_or_exit(p: &Path) -> PathBuf {
+    std::fs::canonicalize(p).unwrap_or_else(|e| {
+        eprintln!("error: cannot resolve path '{}': {e}", p.display());
+        process::exit(1);
+    })
+}
+
 fn resolve_binary(name: &OsStr) -> Option<PathBuf> {
     let path = PathBuf::from(name);
     if path.is_absolute() || path.components().count() > 1 {