Non-stop "Loading commit data" in 5.2

Created by: drakeguan

I believe there is something specific to my setup. I have run through all possible check mentioned in https://github.com/gitlabhq/gitlabhq/blob/master/doc/raketasks/maintenance.md and nearly every checks passed except bundle exec rake gitlab:app:check RAILS_ENV=production

Redis version >= 2.0.0? ... yes
rake aborted!
undefined method `match' for nil:NilClass
/home/git/gitlab/lib/gitlab/version_info.rb:8:in `parse'
/home/git/gitlab/lib/tasks/gitlab/check.rake:671:in `check_git_version'
/home/git/gitlab/lib/tasks/gitlab/check.rake:27:in `block (3 levels) in <top (required)>'

I then go checking production log in admin/log and found out the following stuff:

ActionView::Template::Error (undefined method `committed_date' for nil:NilClass):
4:
5: :plain
6: var row = $("table.table_#{@hex_path} tr.file_#{hexdigest(file_name)}");
7: row.find("td.tree_time_ago").html('#{escape_javascript time_ago_in_words(commit.committed_date)} ago');
8: row.find("td.tree_commit").html('#{escape_javascript render("tree/tree_commit_column", commit: commit)}');
app/views/refs/logs_tree.js.haml:7:in `block in _app_views_refs_logs_tree_js_haml__1324518347852395915_51408880'
app/views/refs/logs_tree.js.haml:1:in `each'
app/views/refs/logs_tree.js.haml:1:in `_app_views_refs_logs_tree_js_haml__1324518347852395915_51408880'

Wondering if there is something data migration issue or mistakes I have done. Looking forward any hints or help for this.