diff --git a/command.go b/command.go
index 3fd0827..2a8fa35 100644
--- a/command.go
+++ b/command.go
@@ -13,6 +13,11 @@ func cmdHead(config configCollect) {
   rc.CollectContent()
   rc.BuildGraph()
   log.Println("Repo has", len(rc.Root), "sources")
+  if len(rc.Root) > 1 {
+    for cn, _ := range rc.Root {
+      log.Println("Commit "+cn.Id+"\n"+cn.Content.String()) 
+    }
+  }
 
   rc.FindLeafs()
   log.Println("Repo has", len(rc.Leafs), "sinks")
diff --git a/commit.go b/commit.go
index a59c1db..b3ee445 100644
--- a/commit.go
+++ b/commit.go
@@ -22,6 +22,7 @@ type RepoCommits struct {
 }
 
 type CommitNode struct {
+  Id string
   Parents map[*CommitNode]Empty
   Children map[*CommitNode]Empty
   Content Commit
@@ -44,15 +45,23 @@ type Commit struct {
   Version int `json:"version"`
 }
 
+func nilable(s *string) string {
+  if s == nil {
+    return "<nil>"
+  } else {
+    return *s
+  }
+}
+
 func (c* Commit) String() string {
-  return fmt.Sprintf(`RootId: %s
-CreatorName: %s
-Creator: %s
-Description: %s
-Ctime: %s
-RepoName: %s
-RepoDesc: %s
-`, *c.RootId, *c.CreatorName, *c.Creator, *c.Description, time.Unix(c.Ctime, 0), *c.RepoName, *c.RepoDesc)
+  return fmt.Sprintf(`RootId: %v
+CreatorName: %v
+Creator: %v
+Description: %v
+Ctime: %v
+RepoName: %v
+RepoDesc: %v
+`, nilable(c.RootId), nilable(c.CreatorName), nilable(c.Creator), nilable(c.Description), time.Unix(c.Ctime, 0), nilable(c.RepoName), nilable(c.RepoDesc))
 }
 
 func NewRepoCommits (config configCollect) *RepoCommits {
@@ -81,9 +90,10 @@ func (rc* RepoCommits) CollectDescs() {
   }
 }
 
-func NewCommitNode(c Commit) *CommitNode {
+func NewCommitNode(c Commit, id string) *CommitNode {
   cn := new(CommitNode)
   cn.Content = c
+  cn.Id = id
   cn.Parents = make(map[*CommitNode]Empty)
   cn.Children = make(map[*CommitNode]Empty)
 
@@ -96,8 +106,11 @@ func (rc* RepoCommits) CollectContent() {
     if err != nil { log.Fatal(err) }
 
     var c Commit;
-    json.Unmarshal(data, &c)
-    rc.CommitContent[id] = NewCommitNode(c)
+    err := json.Unmarshal(data, &c)
+    if err != nil {
+      log.Fatal(err)
+    }
+    rc.CommitContent[id] = NewCommitNode(c,id)
   }
 }