From 6a51e27bb578081119f511fefcc77c87bc8c627c Mon Sep 17 00:00:00 2001
From: Joshua Liebow-Feeser <joshlf@google.com>
Date: Thu, 12 Feb 2026 14:05:58 +0000
Subject: [PATCH] [hermes] Remove diagnostic path mapping from shadow copy

gherrit-pr-id: Gl2u5imkbil27nran4i72sxo5dzpixijo
---
 tools/hermes/src/charon.rs      |  6 +-----
 tools/hermes/src/diagnostics.rs | 10 ++--------
 2 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/tools/hermes/src/charon.rs b/tools/hermes/src/charon.rs
index 7096783802..6798fb533c 100644
--- a/tools/hermes/src/charon.rs
+++ b/tools/hermes/src/charon.rs
@@ -116,11 +116,7 @@ pub fn run_charon(args: &Args, roots: &Roots, packages: &[HermesArtifact]) -> Re
         if let Some(stdout) = child.stdout.take() {
             let reader = BufReader::new(stdout);
 
-            let mut mapper = crate::diagnostics::DiagnosticMapper::new(
-                roots.workspace.clone(),
-                roots.workspace.clone(),
-            );
-
+            let mut mapper = crate::diagnostics::DiagnosticMapper::new(roots.workspace.clone());
             for line in reader.lines() {
                 if let Ok(line) = line {
                     if let Ok(msg) = serde_json::from_str::<cargo_metadata::Message>(&line) {
diff --git a/tools/hermes/src/diagnostics.rs b/tools/hermes/src/diagnostics.rs
index a971d9b0af..cca4e656ad 100644
--- a/tools/hermes/src/diagnostics.rs
+++ b/tools/hermes/src/diagnostics.rs
@@ -9,7 +9,6 @@ use miette::{NamedSource, Report, SourceOffset};
 use thiserror::Error;
 
 pub struct DiagnosticMapper {
-    shadow_root: PathBuf,
     user_root: PathBuf,
     user_root_canonical: PathBuf,
     source_cache: HashMap<PathBuf, String>,
@@ -53,10 +52,10 @@ impl miette::Diagnostic for MappedError {
 }
 
 impl DiagnosticMapper {
-    pub fn new(shadow_root: PathBuf, user_root: PathBuf) -> Self {
+    pub fn new(user_root: PathBuf) -> Self {
         let user_root_canonical =
             fs::canonicalize(&user_root).unwrap_or_else(|_| user_root.clone());
-        Self { shadow_root, user_root, user_root_canonical, source_cache: HashMap::new() }
+        Self { user_root, user_root_canonical, source_cache: HashMap::new() }
     }
 
     pub fn map_path(&self, path: &Path) -> Option<PathBuf> {
@@ -65,11 +64,6 @@ impl DiagnosticMapper {
             p = self.user_root.join(p);
         }
 
-        // Strategy A: Starts with shadow_root
-        if let Ok(suffix) = p.strip_prefix(&self.shadow_root) {
-            return Some(self.user_root.join(suffix));
-        }
-
         // Strategy B: Starts with user_root or user_root_canonical
         if p.starts_with(&self.user_root) || p.starts_with(&self.user_root_canonical) {
             return Some(p);