From d9e227e98ac123b9632b61c4c68afba9748ff584 Mon Sep 17 00:00:00 2001
From: jyn <rust@jyn.dev>
Date: Sun, 26 Apr 2026 16:18:45 +0000
Subject: [PATCH 1/2] Fix broken logic in `incremental_verify_ich_failed`

---
 compiler/rustc_middle/src/error.rs      | 2 +-
 compiler/rustc_middle/src/verify_ich.rs | 8 +++++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/compiler/rustc_middle/src/error.rs b/compiler/rustc_middle/src/error.rs
index 90af4d785945b..29ec97a6ca592 100644
--- a/compiler/rustc_middle/src/error.rs
+++ b/compiler/rustc_middle/src/error.rs
@@ -143,7 +143,7 @@ pub(crate) struct Reentrant;
 #[note(
     "an ideal reproduction consists of the code before and some patch that then triggers the bug when applied and compiled again"
 )]
-#[note("as a workaround, you can run {$run_cmd} to allow your project to compile")]
+#[note("as a workaround, you can {$run_cmd} to allow your project to compile")]
 pub(crate) struct IncrementCompilation {
     pub run_cmd: String,
     pub dep_node: String,
diff --git a/compiler/rustc_middle/src/verify_ich.rs b/compiler/rustc_middle/src/verify_ich.rs
index a1ab4d8cc4d00..5aa7a1d91f800 100644
--- a/compiler/rustc_middle/src/verify_ich.rs
+++ b/compiler/rustc_middle/src/verify_ich.rs
@@ -1,6 +1,8 @@
 use std::cell::Cell;
 
 use rustc_data_structures::fingerprint::Fingerprint;
+use rustc_hir::def_id::LOCAL_CRATE;
+use rustc_session::utils::was_invoked_from_cargo;
 use tracing::instrument;
 
 use crate::dep_graph::{DepGraphData, SerializedDepNodeIndex};
@@ -66,10 +68,10 @@ fn incremental_verify_ich_failed<'tcx>(
     if old_in_panic {
         tcx.dcx().emit_err(crate::error::Reentrant);
     } else {
-        let run_cmd = if let Some(crate_name) = &tcx.sess.opts.crate_name {
-            format!("`cargo clean -p {crate_name}` or `cargo clean`")
+        let run_cmd = if was_invoked_from_cargo() {
+            format!("run `cargo clean -p {}` or `cargo clean`", tcx.crate_name(LOCAL_CRATE))
         } else {
-            "`cargo clean`".to_string()
+            "clean your build cache".to_owned()
         };
 
         let dep_node = tcx.dep_graph.data().unwrap().prev_node_of(prev_index);

From 7151184b46b05a5c96c70d104095c79e6d89aee4 Mon Sep 17 00:00:00 2001
From: jyn <rust@jyn.dev>
Date: Sun, 26 Apr 2026 16:19:11 +0000
Subject: [PATCH 2/2] Add some debugging to `rustc_session` filename handling

---
 compiler/rustc_session/src/config.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index d84bfeb8fff86..cd9d573957f45 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -1205,6 +1205,7 @@ impl OutputFilenames {
     }
 
     pub fn interface_path(&self) -> PathBuf {
+        debug!("using crate_name={} for interface_path", self.crate_stem);
         self.out_directory.join(format!("lib{}.rs", self.crate_stem))
     }
 
@@ -1214,6 +1215,7 @@ impl OutputFilenames {
         let extension = flavor.extension();
         match flavor {
             OutputType::Metadata => {
+                debug!("using crate_name={} for {extension}", self.crate_stem);
                 self.out_directory.join(format!("lib{}.{}", self.crate_stem, extension))
             }
             _ => self.with_directory_and_extension(&self.out_directory, extension),
@@ -1288,6 +1290,7 @@ impl OutputFilenames {
     }
 
     pub fn with_directory_and_extension(&self, directory: &Path, extension: &str) -> PathBuf {
+        debug!("using filestem={} for {extension}", self.filestem);
         let mut path = directory.join(&self.filestem);
         path.set_extension(extension);
         path