metrics: Skip revisions with corrupt dvc.lock files

dvc/repo/metrics/show.py

@@ -1,6 +1,7 @@
 import logging
 from typing import List
 
+from dvc.dvcfile import LockfileCorruptedError
 from dvc.exceptions import (
     MetricDoesNotExistError,
     NoMetricsFoundError,
@@ -35,14 +36,22 @@ def _to_path_infos(metrics: List[BaseOutput]) -> List[PathInfo]:
 
 
 def _collect_metrics(repo, targets, revision, recursive):
-    metrics, path_infos = collect(
-        repo,
-        targets=targets,
-        output_filter=_is_metric,
-        recursive=recursive,
-        rev=revision,
-    )
-    return _to_path_infos(metrics) + list(path_infos)
+    try:
+        metrics, path_infos = collect(
+            repo,
+            targets=targets,
+            output_filter=_is_metric,
+            recursive=recursive,
+            rev=revision,
+        )
+
+        return _to_path_infos(metrics) + list(path_infos)
+
+    except LockfileCorruptedError:
+        logger.warning(
+            "Corrupt lockfile at revision %s. Ignoring in metrics.", revision
+        )
+        return []
 
 
 def _extract_metrics(metrics, path, rev):

tests/func/metrics/test_show.py

@@ -1,4 +1,5 @@
 import os
+import shutil
 
 import pytest
 
@@ -226,3 +227,26 @@ def test_metrics_show_overlap(
 
     with pytest.raises(OverlappingOutputPathsError):
         dvc.metrics.show()
+
+
+def test_skips_broken_commits(tmp_dir, scm, dvc):
+    dvc.run(
+        cmd="echo foo: 1.1 > metrics.yaml",
+        metrics=["metrics.yaml"],
+        name="test",
+    )
+    scm.add(["dvc.yaml", ".gitignore", "dvc.lock"])
+    scm.commit("initial")
+
+    shutil.copyfile("dvc.lock", "dvc.lock.bak")
+    tmp_dir.gen("dvc.lock", "<<<<< broken commit")
+    scm.add(["dvc.lock"])
+    scm.commit("accidental broken commit")
+
+    shutil.copyfile("dvc.lock.bak", "dvc.lock")
+    scm.add(["dvc.lock"])
+    scm.commit("revert breakage")
+
+    assert list(dvc.metrics.show(all_commits=True).values())[0] == {
+        "metrics.yaml": {"foo": 1.1}
+    }