title: Running tmux on an M1 Mac in arm64 mode
body: <p>So I have tmux installed via arm64 homebrew.</p>
  <p>I initially compiled alacritty (my favorite terminal emulator) for arm64 manually, so that's running in arm64 mode. <code>uname -a</code> confirms we're in arm64.</p>
  <pre><code>Darwin ndo-mbp.local 20.1.0 Darwin Kernel Version 20.1.0: Sat Oct 31 00:07:10 PDT 2020; root:xnu-7195.50.7~2/RELEASE_ARM64_T8101 arm64
  </code></pre>
  <p>Then I installed homebrew which slowly but surely getting arm64 bottles for most popular applications, including <code>tmux</code> (<a href="https://github.com/Homebrew/brew/issues/7857" rel="noreferrer">https://github.com/Homebrew/brew/issues/7857</a>). So I installed that from the arm64 shell, it compiled successfully.</p>
  <p>If I run <code>file $(which tmux)</code> I get:</p>
  <pre><code>/opt/homebrew/bin/tmux: Mach-O 64-bit executable arm64
  </code></pre>
  <p>However, if I launch that <code>tmux</code> binary in my arm64 alacritty, I seem to land in x86_64 mode. Running <code>uname -a</code> from inside that tmux window I get:</p>
  <pre><code>Darwin ndo-mbp.local 20.1.0 Darwin Kernel Version 20.1.0: Sat Oct 31 00:07:10 PDT 2020; root:xnu-7195.50.7~2/RELEASE_ARM64_T8101 x86_64
  </code></pre>
  <p>Any idea what's going on here? I'm relatively new to Mac OS, so maybe I'm missing something obvious.</p>