diff --git a/rust/crates/pumas-core/src/discovery/tests.rs b/rust/crates/pumas-core/src/discovery/tests.rs
index 4385ac0a..08508f46 100644
--- a/rust/crates/pumas-core/src/discovery/tests.rs
+++ b/rust/crates/pumas-core/src/discovery/tests.rs
@@ -503,12 +503,29 @@ async fn ordinary_drop_retains_owner_until_real_finite_index_mutation_and_ipc_se
         .is_err());
     // This diagnostic handle still owns the mutable library after settlement.
     drop(primary);
-    let successor = attach_or_start(
-        registry.clone(),
-        &root,
-        &CompatibilityRequirements::default(),
-    )
+    // Dropping the owner does not release the native store lock immediately:
+    // a child spawned by a parallel test can briefly inherit its descriptor.
+    // Only that busy refusal is retried, within a bound.
+    let successor = tokio::time::timeout(std::time::Duration::from_secs(5), async {
+        loop {
+            match attach_or_start(
+                registry.clone(),
+                &root,
+                &CompatibilityRequirements::default(),
+            )
+            .await
+            {
+                Err(crate::PumasError::InvalidParams { message })
+                    if message.contains("already running for physical store") =>
+                {
+                    tokio::time::sleep(std::time::Duration::from_millis(20)).await;
+                }
+                other => break other,
+            }
+        }
+    })
     .await
+    .expect("physical store lease was not released after the owner dropped")
     .unwrap();
     assert!(matches!(&successor, LocalAccess::Owned { .. }));
     successor.shutdown_owned().await.unwrap();
diff --git a/rust/crates/pumas-core/src/model_library/identifier.rs b/rust/crates/pumas-core/src/model_library/identifier.rs
index 2dbdb88c..d0025d4f 100644
--- a/rust/crates/pumas-core/src/model_library/identifier.rs
+++ b/rust/crates/pumas-core/src/model_library/identifier.rs
@@ -209,8 +209,20 @@ fn identify_gguf<R: Read + Seek>(file: &mut R, path: &Path) -> Result<ModelTypeI
     // Then: metadata key-value pairs
 
     let mut header = [0u8; 24];
-    file.read_exact(&mut header)
-        .map_err(|e| PumasError::io_with_path(e, path))?;
+    match file.read_exact(&mut header) {
+        Ok(()) => {}
+        // Too short for a GGUF header: malformed content, not a failed read.
+        // Validation reports the unusable file; import must not fail on it.
+        Err(error) if error.kind() == std::io::ErrorKind::UnexpectedEof => {
+            return Ok(ModelTypeInfo {
+                format: FileFormat::Gguf,
+                model_type: ModelType::Unknown,
+                family: None,
+                extra: HashMap::new(),
+            });
+        }
+        Err(error) => return Err(PumasError::io_with_path(error, path)),
+    }
 
     let version = u32::from_le_bytes(header[4..8].try_into().unwrap());
     let metadata_count = u64::from_le_bytes(header[16..24].try_into().unwrap());
@@ -1033,6 +1045,23 @@ pub fn extract_gguf_metadata(path: impl AsRef<Path>) -> Result<HashMap<String, S
 mod tests {
     use super::*;
 
+    #[test]
+    fn truncated_gguf_is_identified_as_unknown_not_an_io_failure() {
+        // A .gguf too short for its header (here, no GGUF magic at all) is
+        // malformed content; identification must not fail the import.
+        let temp = tempfile::tempdir().unwrap();
+        let path = temp.path().join("weights.gguf");
+        std::fs::write(&path, b"retained artifact").unwrap();
+        let info = identify_model_type(&path).unwrap();
+        assert_eq!(info.format, FileFormat::Gguf);
+        assert_eq!(info.model_type, ModelType::Unknown);
+        std::fs::write(&path, b"GGUF\x03\x00\x00\x00").unwrap();
+        assert_eq!(
+            identify_model_type(&path).unwrap().model_type,
+            ModelType::Unknown
+        );
+    }
+
     #[test]
     fn acquired_descriptor_identification_ignores_unselected_context() {
         let temp = tempfile::tempdir().unwrap();
diff --git a/rust/crates/pumas-core/src/runtime_profiles/process_owner.rs b/rust/crates/pumas-core/src/runtime_profiles/process_owner.rs
index b4d6844d..7639e258 100644
--- a/rust/crates/pumas-core/src/runtime_profiles/process_owner.rs
+++ b/rust/crates/pumas-core/src/runtime_profiles/process_owner.rs
@@ -1329,7 +1329,19 @@ mod tests {
         assert!(custody.drain(Duration::from_secs(5)).unwrap());
         assert!(!custody.is_active());
         assert!(!custody.has_parked_child());
-        let after_confirmed_drain = PhysicalStoreLease::try_acquire(&store);
+        // A child forked by a parallel test briefly holds an inherited copy of
+        // the lock until its exec closes it, so release is awaited (bounded).
+        let release_deadline = std::time::Instant::now() + Duration::from_secs(5);
+        let after_confirmed_drain = loop {
+            let attempt = PhysicalStoreLease::try_acquire(&store);
+            if !matches!(&attempt, Err(StoreLeaseError::Busy(_)))
+                || std::time::Instant::now() >= release_deadline
+            {
+                break attempt;
+            }
+            drop(attempt);
+            std::thread::sleep(Duration::from_millis(10));
+        };
         assert!(
             after_confirmed_drain.is_ok(),
             "confirmed fixture drain did not release physical store: {after_confirmed_drain:?}"