From ed715b7ff671129d55fee7bcc7665dfbb51ec963 Mon Sep 17 00:00:00 2001
From: Matthew Jackson <1085847+MattJackson@users.noreply.github.com>
Date: Mon, 28 Sep 2026 12:26:20 -0700
Subject: [PATCH] test: fvi pipeline tests hold the Drive-holder lock; the lock
 exists under loom too

---
 src/halt.rs                   | 3 ++-
 src/mux/fvi_pipeline_tests.rs | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/halt.rs b/src/halt.rs
index cd1e375b..f7771e89 100644
--- a/src/halt.rs
+++ b/src/halt.rs
@@ -538,7 +538,8 @@ pub fn live_drive_holders() -> usize {
 }
 
 // Every test that spawns a Drive holder or reads the process-wide count holds this.
-#[cfg(all(test, not(loom)))]
+#[cfg(test)]
+#[cfg_attr(loom, allow(dead_code))]
 pub(crate) static DRIVE_HOLDER_TEST_LOCK: std::sync::Mutex<()> = std::sync::Mutex::new(());
 
 /// A thread that holds the Drive (§2.5): the op joins it before returning. In debug
diff --git a/src/mux/fvi_pipeline_tests.rs b/src/mux/fvi_pipeline_tests.rs
index 4509adee..9e83b001 100644
--- a/src/mux/fvi_pipeline_tests.rs
+++ b/src/mux/fvi_pipeline_tests.rs
@@ -171,6 +171,7 @@ fn two_gop_image() -> Vec<u8> {
 
 /// Drive the real highway and write every frame into the `fvi://` sink.
 fn run_to_fvi(image: Vec<u8>, title: DiscTitle, path: &std::path::Path) {
+    let _drive = crate::sector::prefetched::holder_test_lock();
     let mut input = build_iso_pipeline(
         MemSource { data: image },
         title.clone(),