ignore search commit data for repo clients which dont support it

The primary data is the configuration files and the search commit data
is just extra, so better to return some data than no data in this case.

Signed-off-by: Spencer Schrock <sschrock@google.com>

checks/dependency_update_tool_test.go

@@ -162,3 +162,21 @@ func TestDependencyUpdateTool(t *testing.T) {
 		})
 	}
 }
+
+func TestDependencyUpdateTool_noSearchCommits(t *testing.T) {
+	t.Parallel()
+	ctrl := gomock.NewController(t)
+	mockRepo := mockrepo.NewMockRepoClient(ctrl)
+	files := []string{"README.md"}
+	mockRepo.EXPECT().ListFiles(gomock.Any()).Return(files, nil)
+	mockRepo.EXPECT().SearchCommits(gomock.Any()).Return(nil, clients.ErrUnsupportedFeature)
+	dl := scut.TestDetailLogger{}
+	c := &checker.CheckRequest{
+		RepoClient: mockRepo,
+		Dlogger:    &dl,
+	}
+	got := DependencyUpdateTool(c)
+	if got.Error != nil {
+		t.Errorf("got: %v, wanted ErrUnsupportedFeature not to propagate", got.Error)
+	}
+}

checks/raw/dependency_update_tool.go

@@ -15,6 +15,7 @@
 package raw
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
@@ -42,7 +43,13 @@ func DependencyUpdateTool(c clients.RepoClient) (checker.DependencyUpdateToolDat
 
 	commits, err := c.SearchCommits(clients.SearchCommitsOptions{Author: "dependabot[bot]"})
 	if err != nil {
-		return checker.DependencyUpdateToolData{}, fmt.Errorf("%w", err)
+		// TODO https://github.com/ossf/scorecard/issues/1709
+		// some repo clients (e.g. local) don't currently have the ability to search commits,
+		// but some data is better than none.
+		if errors.Is(err, clients.ErrUnsupportedFeature) {
+			return checker.DependencyUpdateToolData{Tools: tools}, nil
+		}
+		return checker.DependencyUpdateToolData{}, fmt.Errorf("dependabot commit search: %w", err)
 	}
 
 	for i := range commits {