ci: lint all targets, run interop suites for real, compile benches

- clippy --all-targets plus a clawhdf5-format feature matrix (parallel, lz4,
  zstd, pcodec, fast-checksum); fix the accumulated lint backlog in test,
  bench and feature-gated code (no behaviour changes).
- Install python3 + h5py/numpy/netCDF4/xarray in the CI container and set
  CLAWHDF5_REQUIRE_INTEROP=1, which makes a missing interop dependency a test
  failure. Every h5py/netCDF4 interop test used to skip silently in CI. Run
  the #[ignore]d writer_h5py_tests suite explicitly.
- cargo bench --no-run so benches can't rot; fix bench.rs and memory_bench.rs,
  which no longer compiled against the current strategy/consolidation APIs.
- Optional fuzz smoke run via CLAWHDF5_FUZZ_SECONDS.
- CHANGELOG and docs/known-issues.md updated.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

crates/clawhdf5-format/tests/integration_test.rs

@@ -343,7 +343,11 @@ fn attrs_h5_dataset_scale() {
     let scale_attr = find_attribute(&attrs, "scale").expect("scale attr not found");
     let vals = scale_attr.read_as_f64().unwrap();
     assert_eq!(vals.len(), 1);
-    assert!((vals[0] - 3.14).abs() < 1e-10);
+    // 3.14 here is the literal value baked into the binary fixture (fixtures/attrs.h5),
+    // not an arbitrary sample value, so it cannot be swapped for another constant.
+    #[allow(clippy::approx_constant)]
+    let expected = 3.14;
+    assert!((vals[0] - expected).abs() < 1e-10);
 }
 
 #[test]
@@ -556,8 +560,8 @@ fn chunked_deflate_read_values() {
     let (raw, datatype, _) = read_chunked_dataset(file_data, "data");
     let values = read_as_f64(&raw, &datatype).unwrap();
     assert_eq!(values.len(), 100);
-    for i in 0..100 {
-        assert_eq!(values[i], i as f64, "mismatch at index {i}");
+    for (i, &v) in values.iter().enumerate() {
+        assert_eq!(v, i as f64, "mismatch at index {i}");
     }
 }
 
@@ -567,8 +571,8 @@ fn chunked_shuffle_deflate_read_values() {
     let (raw, datatype, _) = read_chunked_dataset(file_data, "data");
     let values = read_as_f64(&raw, &datatype).unwrap();
     assert_eq!(values.len(), 100);
-    for i in 0..100 {
-        assert_eq!(values[i], i as f64, "mismatch at index {i}");
+    for (i, &v) in values.iter().enumerate() {
+        assert_eq!(v, i as f64, "mismatch at index {i}");
     }
 }
 
@@ -578,8 +582,8 @@ fn chunked_fletcher32_read_values() {
     let (raw, datatype, _) = read_chunked_dataset(file_data, "data");
     let values = read_as_f64(&raw, &datatype).unwrap();
     assert_eq!(values.len(), 100);
-    for i in 0..100 {
-        assert_eq!(values[i], i as f64, "mismatch at index {i}");
+    for (i, &v) in values.iter().enumerate() {
+        assert_eq!(v, i as f64, "mismatch at index {i}");
     }
 }
 
@@ -589,11 +593,10 @@ fn chunked_2d_read_values() {
     let (raw, datatype, _) = read_chunked_dataset(file_data, "matrix");
     let values = read_as_f32(&raw, &datatype).unwrap();
     assert_eq!(values.len(), 60);
-    for i in 0..60 {
+    for (i, &v) in values.iter().enumerate() {
         assert!(
-            (values[i] - i as f32).abs() < 1e-6,
-            "mismatch at index {i}: got {}",
-            values[i]
+            (v - i as f32).abs() < 1e-6,
+            "mismatch at index {i}: got {v}"
         );
     }
 }
@@ -604,8 +607,8 @@ fn chunked_large_read_values() {
     let (raw, datatype, _) = read_chunked_dataset(file_data, "big");
     let values = read_as_i32(&raw, &datatype).unwrap();
     assert_eq!(values.len(), 1000);
-    for i in 0..1000 {
-        assert_eq!(values[i], i as i32, "mismatch at index {i}");
+    for (i, &v) in values.iter().enumerate() {
+        assert_eq!(v, i as i32, "mismatch at index {i}");
     }
 }
 
@@ -615,8 +618,8 @@ fn chunked_nofilter_read_values() {
     let (raw, datatype, _) = read_chunked_dataset(file_data, "raw");
     let values = read_as_f64(&raw, &datatype).unwrap();
     assert_eq!(values.len(), 50);
-    for i in 0..50 {
-        assert_eq!(values[i], i as f64, "mismatch at index {i}");
+    for (i, &v) in values.iter().enumerate() {
+        assert_eq!(v, i as f64, "mismatch at index {i}");
     }
 }
 
@@ -646,8 +649,8 @@ fn v4_implicit_read() {
     let (raw, datatype, _) = read_chunked_dataset(file_data, "data");
     let values = read_as_f64(&raw, &datatype).unwrap();
     assert_eq!(values.len(), 100);
-    for i in 0..100 {
-        assert_eq!(values[i], i as f64, "mismatch at index {i}");
+    for (i, &v) in values.iter().enumerate() {
+        assert_eq!(v, i as f64, "mismatch at index {i}");
     }
 }
 
@@ -657,8 +660,8 @@ fn v4_fixed_array_read() {
     let (raw, datatype, _) = read_chunked_dataset(file_data, "data");
     let values = read_as_f64(&raw, &datatype).unwrap();
     assert_eq!(values.len(), 100);
-    for i in 0..100 {
-        assert_eq!(values[i], i as f64, "mismatch at index {i}");
+    for (i, &v) in values.iter().enumerate() {
+        assert_eq!(v, i as f64, "mismatch at index {i}");
     }
 }
 
@@ -871,11 +874,10 @@ fn v4_2d_fixed_array_read() {
     let (raw, datatype, _) = read_chunked_dataset(file_data, "matrix");
     let values = read_as_f32(&raw, &datatype).unwrap();
     assert_eq!(values.len(), 60);
-    for i in 0..60 {
+    for (i, &v) in values.iter().enumerate() {
         assert!(
-            (values[i] - i as f32).abs() < 1e-6,
-            "mismatch at index {i}: got {}",
-            values[i]
+            (v - i as f32).abs() < 1e-6,
+            "mismatch at index {i}: got {v}"
         );
     }
 }
@@ -1272,7 +1274,7 @@ fn write_roundtrip_scalar_f64_attr() {
     let mut fw = FileWriter::new();
     fw.create_dataset("data")
         .with_f64_data(&[1.0])
-        .set_attr("scale", AttrValue::F64(3.14));
+        .set_attr("scale", AttrValue::F64(3.25));
     let bytes = fw.finish().unwrap();
 
     let sig = find_signature(&bytes).unwrap();
@@ -1283,7 +1285,7 @@ fn write_roundtrip_scalar_f64_attr() {
     let scale = find_attribute(&attrs, "scale").expect("scale attr not found");
     let vals = scale.read_as_f64().unwrap();
     assert_eq!(vals.len(), 1);
-    assert!((vals[0] - 3.14).abs() < 1e-10);
+    assert!((vals[0] - 3.25).abs() < 1e-10);
 }
 
 #[test]

crates/clawhdf5-format/tests/reference_tests.rs

@@ -180,15 +180,20 @@ print('ok')
     let output = match output {
         Ok(o) if o.status.success() => o,
         _ => {
+            // CI sets CLAWHDF5_REQUIRE_INTEROP=1 so this can't silently skip.
+            assert!(
+                !std::env::var("CLAWHDF5_REQUIRE_INTEROP").is_ok_and(|v| v == "1"),
+                "CLAWHDF5_REQUIRE_INTEROP=1 but python3 with h5py is not available"
+            );
             eprintln!("skipping h5py_object_reference_roundtrip: python3+h5py not available");
             return;
         }
     };
     let stdout = String::from_utf8(output.stdout).unwrap();
-    if !stdout.trim().contains("ok") {
-        eprintln!("skipping h5py_object_reference_roundtrip: h5py script failed");
-        return;
-    }
+    assert!(
+        stdout.trim().contains("ok"),
+        "h5py reference-file generator did not report ok: {stdout}"
+    );
 
     // Read the file and parse object references
     let file_data = std::fs::read(&path).unwrap();