title: error: mainline was specified but commit is not a merge; fatal: revert failed
body: <p>I want to revert the reverted pull requests i.e. the 4 commits <code>6283c90</code>, <code>f665a5a</code>, <code>09ed268</code>, <code>05ed1bc</code>.</p>
  <p>But when I use the command <code>git revert -m 1 6283c90</code>, I am running into the following error:</p>
  <pre><code>error: mainline was specified but commit 6283c90bd35598635fe1d4f96d3a5a8c6ed91206 is not a merge.
  fatal: revert failed
  </code></pre>
  <p>The git log graph looks something like below:</p>
  <pre><code>* 6283c90 (HEAD -&gt; main, origin/main, origin/HEAD) Revert &quot;Merge pull request #1 from kgarg8/checkpoint-patch&quot;
  * f665a5a Revert &quot;Merge pull request #2 from kgarg8/entmax-patch&quot;
  * 09ed268 Revert &quot;Merge pull request #3 from kgarg8/decoding&quot;
  * 05ed1bc Revert &quot;Merge pull request #4 from kgarg8/decoding&quot;
  *   2a8519e Merge pull request #4 from kgarg8/decoding
  |\  
  | * e170320 (origin/decoding) Fix bugs in decoding
  * |   63f0f4c Merge pull request #3 from kgarg8/decoding
  |\ \  
  | |/  
  | * f5ce256 Add temperature, top_k, top_p sampling
  * |   168685e Merge pull request #2 from kgarg8/entmax-patch
  |\ \  
  | |/  
  | * 6a44c22 (origin/entmax-patch) Add entmax support
  * |   7f61831 Merge pull request #1 from kgarg8/checkpoint-patch
  |\ \  
  | |/  
  | * ea0a7db (origin/checkpoint-patch) Checkpoint load for CPU
  |/  
  * 4c2d50c Update Seq2Seq_agent.py
  ... continues
  </code></pre>
  <p>Any help will be appreciated.</p>