title: boost::filesystem not working in Google Cloud Run (using gVisor)
body: <p>I've created a docker container (<code>ubuntu:focal</code>) with a C++ application that is using <code>boost::filesystem</code> (v1.76.0) to create some directories while processing data. It works if I run the container locally, but it fails when deployed to Cloud Run.</p>
  <p>A simple statement like</p>
  <pre><code>boost::filesystem::exists(boost::filesystem::current_path())
  </code></pre>
  <p>fails with <em>&quot;Invalid argument '/current/path/here'&quot;</em>. <strong>It doesn't work in this C++ application, but from a Python app running equivalent statements, it does work.</strong></p>
  <p>Reading <a href="https://cloud.google.com/run/docs/reference/container-contract#sandbox" rel="nofollow noreferrer">the docs</a> I can see Cloud Run is using gVisor and not all the system calls are fully supported (link: <a href="https://gvisor.dev/docs/user_guide/compatibility/linux/amd64/" rel="nofollow noreferrer">https://gvisor.dev/docs/user_guide/compatibility/linux/amd64/</a>), nevertheless I would expect simple calls to work: check if a directory exists, create a directory, remove,...</p>
  <p>Maybe I'm doing something wrong when deploying my container. Is there any way to work around it? Any <code>boost</code> configuration I can use to prevent it from using some syscalls?</p>
  <p>Thanks for your help!</p>