Ubuntu 1604更新軟體提示W

最近用 Ubuntu 14.04更新軟體的時候，升級軟體源列表，在終端下執行下述程式碼：

<code class="hljs bash has-numbering"><span class="hljs-built_in">sudo</span> apt-get update</code><ul style="" class="pre-numbering"><li>1</li></ul>

會出現如下的錯誤：

<code class="hljs vhdl has-numbering">W: GPG error: http://archive.ubuntukylin.com:<span class="hljs-number">10006</span> xenial InRelease: The following signatures couldn<span class="hljs-attribute">'t</span> be verified because the public key <span class="hljs-keyword">is</span> <span class="hljs-keyword">not</span> available: NO_PUBKEY <span class="hljs-number">8</span>D5A09DC9B929006</code><ul style="" class="pre-numbering"><li>1</li></ul>

經過谷歌發現是金鑰的問題，解決辦法：

<code class="hljs brainfuck has-numbering"><span class="hljs-comment">sudo</span> <span class="hljs-comment">apt</span><span class="hljs-literal">-</span><span class="hljs-comment">key</span> <span class="hljs-comment">adv</span> <span class="hljs-literal">-</span><span class="hljs-literal">-</span><span class="hljs-comment">keyserver</span> <span class="hljs-comment">keyserver</span><span class="hljs-string">.</span><span class="hljs-comment">ubuntu</span><span class="hljs-string">.</span><span class="hljs-comment">com</span> <span class="hljs-literal">-</span><span class="hljs-literal">-</span><span class="hljs-comment">recv</span><span class="hljs-literal">-</span><span class="hljs-comment">keys</span> <span class="hljs-comment">8D5A09DC9B929006</span></code><ul style="" class="pre-numbering"><li>1</li></ul>

注意提示的金鑰和你上述命令中的金鑰是一樣的，每個人的電腦都不一樣