回答我自己的问题:

显然我的 SVN URL 有错误的大小写！谷歌搜索出现了一篇文章(不再在线提供)，解释了正在发生的事情.我的 URL 的形式是 http://svn.foobar.com/foobar 但实际的存储库被称为http://svn.foobar.com/fooBar.

Apparently my SVN URL had the wrong case! A Google search turned up an article (no longer available online) that explained what was going on. My URL was of the form http://svn.foobar.com/foobar but the actual repository was called http://svn.foobar.com/fooBar.

我使用 TortoiseSVN，因此修复方法是使用 Relocate 命令来更正存储库的路径.

I use TortoiseSVN, so the fix was to use the Relocate command to correct the path to the repository.

希望这会对其他人有所帮助.

Hopefully this will help someone else.