/usr/share/mercurial/templates/gitweb/notfound.tmpl is in mercurial-common 3.7.3-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | {header}
<title>Mercurial repository not found</title>
</head>
<body>
<div class="page_header">
<a href="{logourl}" title="Mercurial" style="float: right;">Mercurial</a> Not found: {repo|escape}
</div>
<div class="page_body">
The specified repository "{repo|escape}" is unknown, sorry.
<br/>
<br/>
Please go back to the <a href="{url|urlescape}">main repository list page</a>.
</div>
{footer}
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