title: Homebrew no available formula or cask : fatal: Needed a single revision
body: <p>notice : sorry if my english is bad (I'm french)</p>
  <p>Hey, I'm on Mac OS and i have a problem with Homebrew.</p>
  <p>I have to install somethings with this command: <code>brew install pkg-config cairo pango libpng jpeg giflib librsvg</code></p>
  <p>But when i do this, i have that :</p>
  <pre><code>Warning: No available formula or cask with the name &quot;ca-certificates&quot;.
  ==&gt; Searching for similarly named formulae...
  Error: No similarly named formulae found.
  ==&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.
  Updating Homebrew...
  fatal: Needed a single revision
  Warning: No available formula or cask with the name &quot;pkg-config&quot;.
  ==&gt; Searching for similarly named formulae...
  Error: No similarly named formulae found.
  ==&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>I have tried to find a solution but it doesn't work.., even if i uninstall and reinstall Homebrew, i have the same problem, then i'm asking if i can install the files i need with another way than Homebrew or also if you have an idea to make my homebrew work correctly but i've give up this idea.., So if you can help me please! thank you.</p>