@@ -141,9 +141,9 @@ func (f File) GodepsRepoChanged() (string, error) {

 func CommitsBetween(a, b string) ([]Commit, error) {

 	commits := []Commit{}

-	stdout, _, err := run("git", "log", "--oneline", fmt.Sprintf("%s..%s", a, b))

+	stdout, stderr, err := run("git", "log", "--oneline", fmt.Sprintf("%s..%s", a, b))

 	if err != nil {

-		return nil, fmt.Errorf("error executing git log: %s", err)

+		return nil, fmt.Errorf("error executing git log: %s: %s", stderr, err)

 	}

 	for _, log := range strings.Split(stdout, "\n") {

 		if len(log) == 0 {

@@ -255,9 +255,9 @@ func CurrentRev(repoDir string) (string, error) {

 func filesInCommit(sha string) ([]File, error) {

 	files := []File{}

-	stdout, _, err := run("git", "diff-tree", "--no-commit-id", "--name-only", "-r", sha)

+	stdout, stderr, err := run("git", "diff-tree", "--no-commit-id", "--name-only", "-r", sha)

 	if err != nil {

-		return nil, err

+		return nil, fmt.Errorf("%s: %s", stderr, err)

 	}

 	for _, filename := range strings.Split(stdout, "\n") {

 		if len(filename) == 0 {