remove panic

src/lib.rs

@@ -373,22 +373,27 @@ fn load_sketches_above_threshold(
     let matchlist: BinaryHeap<PrefetchResult> = sketchlist_paths
         .par_iter()
         .filter_map(|m| {
-            let sigs = Signature::from_path(m).unwrap();
+            let sigs = Signature::from_path(m);
 
             let mut mm = None;
-            for sig in &sigs {
-                if let Some(mh) = prepare_query(sig, template) {
-                    if let Ok(overlap) = mh.count_common(query, false) {
-                        if overlap >= threshold_hashes {
-                            let result = PrefetchResult {
-                                name: sig.name(),
-                                minhash: mh,
-                                overlap,
-                            };
-                            mm = Some(result);
+            if let Ok(sigs) = sigs {
+                for sig in &sigs {
+                    if let Some(mh) = prepare_query(sig, template) {
+                        if let Ok(overlap) = mh.count_common(query, false) {
+                            if overlap >= threshold_hashes {
+                                let result = PrefetchResult {
+                                    name: sig.name(),
+                                    minhash: mh,
+                                    overlap,
+                                };
+                                mm = Some(result);
+                                break;
+                            }
                         }
                     }
                 }
+            } else {
+                 // print out error here...
             }
             mm
         })

src/python/tests/test_gather.py

@@ -159,7 +159,6 @@ def test_missing_against(runtmp, capfd):
 def test_bad_against(runtmp, capfd):
     # test bad 'against' file - in this case, use a .sig.gz file.
     query = get_test_data('SRR606249.sig.gz')
-    against_list = runtmp.output('against.txt')
 
     sig2 = get_test_data('2.fa.sig.gz')
 
@@ -175,3 +174,27 @@ def test_bad_against(runtmp, capfd):
     print(captured.err)
 
     assert 'Error: invalid line in fromfile ' in captured.err
+
+
+
+
+def test_bad_against_2(runtmp, capfd):
+    # test bad 'against' file - in this case, one containing a bad filename.
+    query = get_test_data('SRR606249.sig.gz')
+    against_list = runtmp.output('against.txt')
+
+    sig2 = get_test_data('2.fa.sig.gz')
+    make_file_list(against_list, [sig2, 'file-does-not-exist'])
+
+
+    g_output = runtmp.output('gather.csv')
+    p_output = runtmp.output('prefetch.csv')
+
+    runtmp.sourmash('scripts', 'fastgather', query, against_list,
+                    '-o', g_output, '--output-prefetch', p_output,
+                    '-s', '100000')
+
+    captured = capfd.readouterr()
+    print(captured.err)
+
+    # @CTB: should be some kind of error message here.