矩阵中定义的节点出现“包 pgf 错误：没有已知形状”

Question

在我的本地系统上，\graph 无法识别 \matrix 定义的节点

\documentclass{article} % say
\usepackage{tikz}

\usetikzlibrary{calc,intersections,through,backgrounds}
\usetikzlibrary{arrows,decorations.pathmorphing,backgrounds,positioning,fit,petri}
\usetikzlibrary{shapes.misc}
\usetikzlibrary{graphs}
% \usetikzlibrary{graphs.standard}
% \usetikzlibrary{graphdrawing}

\begin{document}
    \begin{tikzpicture} [scale=1,
            skip_loop/.style={
                to path={-- ++(0,#1) -| (\tikztotarget)}},
            hv_path/.style={
                to path={-| (\tikztotarget)}},
            vh_path/.style={
                to path={|- (\tikztotarget)}},
            nonterminal/.style={
                rectangle,
                minimum size=6mm,
                very thick,
                draw=red!50!black!50,
                top color=white, 
                bottom color=red!50!black!20, 
                font=\itshape},
            terminal/.style={
                rectangle,minimum size=6mm, rounded corners=3mm,
                very thick,draw=black!50,
                top color=white,bottom color=black!20,
                font=\ttfamily},
            point/.style={
                circle,inner sep=0pt,minimum size=2pt,fill=red}
            ]

        \matrix[row sep=2mm,column sep=2mm] {
            % First row:
                & & & & & & & & & & & \node (plus) [terminal] {+}; \\
            % Second row:
                \node (p1) [point] {}; &    \node (ui1)   [nonterminal] {unsigned integer}; &
                \node (p2) [point] {}; &    \node (dot)   [terminal]    {.};                &
                \node (p3) [point] {}; &    \node (digit) [terminal]    {digit};            &
                \node (p4) [point] {}; &    \node (p5)    [point] {};                       &
                \node (p6) [point] {}; &    \node (e)     [terminal]    {E};                &
                \node (p7) [point] {}; &                                                    &
                \node (p8) [point] {}; &    \node (ui2)   [nonterminal] {unsigned integer}; &
                \node (p9) [point] {}; &    \node (p10)   [point] {};                       &\\
            % Third row:
                & & & & & & & & & & & \node (minus) [terminal] {-}; \\
        };

        \graph {
            % (p4)  ->[skip_loop=-5mm] (p3);
            % (p2)  ->[skip_loop=5mm] (p6);
            (p1) -> (ui1) -- (p2) -> (dot) -- (p3) -> (digit) -- (p4)
                 -- (p5) -- (p6) -> (e) -- (p7) -- (p8) -> (ui2) -- (p9) -> (p10);
            (p4) ->[skip_loop=-5mm]     (p3);
            (p2) ->[skip_loop=5mm]      (p5);
            (p6) ->[skip_loop=-11mm]    (p9);
            (p7) ->[vh_path]            (plus) -> [hv_path] (p8);
            (p7) ->[vh_path]            (minus) -> [hv_path] (p8);
        };

    \end{tikzpicture}
\end{document}

该代码在 sharelatex.com 上运行良好，但在我的系统上却出现错误：

./4_graphs.tex:119: Package pgf Error: No shape named (p1 is known. [       }]
./4_graphs.tex:119: Package tikz Error: Giving up on this path. Did you forget a semicolon?. [      }]
./4_graphs.tex:119: Package pgf Error: No shape named (ui1 is known. [      }]
./4_graphs.tex:119: Package tikz Error: Giving up on this path. Did you forget a semicolon?. [      }]
./4_graphs.tex:119: Package pgf Error: No shape named (p2 is known. [       }]
./4_graphs.tex:119: Package tikz Error: Giving up on this path. Did you forget a semicolon?. [      }]
... ... ... ... 
... ... ... ... 
... ... ... ... 
./4_graphs.tex:119: Package pgfkeys Error: I do not know the key '/tikz/graphs/vh_path' and I am going to ignore it. Perhaps you misspelled it. [       }]
./4_graphs.tex:119: Package pgf Error: No shape named (p7 is known. [       }]
./4_graphs.tex:119: Package tikz Error: Giving up on this path. Did you forget a semicolon?. [      }]
./4_graphs.tex:119: Package pgfkeys Error: I do not know the key '/tikz/graphs/hv_path' and I am going to ignore it. Perhaps you misspelled it. [       }]
./4_graphs.tex:119: Package pgf Error: No shape named (minus is known. [        }]
./4_graphs.tex:119: Package tikz Error: Giving up on this path. Did you forget a semicolon?. [      }]

是版本问题吗？我在 ubuntu 14.10 上使用的是默认安装（ver 2013.20140215-1）。