title: Installing upx with Mac Big Sur
body: <p>I'm having trouble installing upx. The following are the steps that I took. My macOs is 11.2.1</p>
  <pre><code> % ruby -e &quot;$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)&quot; &lt; /dev/null 2&gt; /dev/null
  ==&gt; Checking for `sudo` access (which may request your password).
  ==&gt; This script will install:
  /usr/local/bin/brew
  /usr/local/share/doc/homebrew
  /usr/local/share/man/man1/brew.1
  /usr/local/share/zsh/site-functions/_brew
  /usr/local/etc/bash_completion.d/brew
  /usr/local/Homebrew
  ==&gt; /usr/bin/sudo /usr/sbin/chown -R vuduc:admin /usr/local/Homebrew
  ==&gt; Downloading and installing Homebrew...
  HEAD is now at 3ff5795ae Merge pull request #10652 from danielnachun/revert-gcc-linkage-fix
  ==&gt; Installation successful!
  
  ==&gt; Homebrew has enabled anonymous aggregate formulae and cask analytics.
  Read the analytics documentation (and how to opt-out) here:
    https://docs.brew.sh/Analytics
  No analytics data has been sent yet (or will be during this `install` run).
  
  ==&gt; Homebrew is run entirely by unpaid volunteers. Please consider donating:
    https://github.com/Homebrew/brew#donations
  
  ==&gt; Next steps:
  - Run `brew help` to get started
  - Further documentation: 
      https://docs.brew.sh
  
  % brew install upx
  Updating Homebrew...
  fatal: Could not resolve HEAD to a revision
  ==&gt; Searching for similarly named formulae...
  Error: No similarly named formulae found.
  Error: No available formula or cask with the name &quot;upx&quot;.
  ==&gt; Searching for a previously deleted formula (in the last month)...
  Error: No previously deleted formula found.
  ==&gt; Searching taps on GitHub...
  Error: No formulae found in taps.
  </code></pre>
  <p>How can I solve this issue? I need to install upx because some apps show &quot;You do not have permission to open the application…&quot; when I tried to run them.</p>