title: Coursier vs Ivy, checksums & SSL exceptions
body: <p>I inherited a Gatling project originally built against v3.2.1, and understand that version 3.3.1 has been released since the project was last actively maintained, so I updated that in the <em>build.sbt</em> file, and started getting &quot;wrong checksum&quot; errors on the command line (e.g. <code>wrong checksum: C:\temp\SSCCE\null\Coursier\cache\v1\https\repo1.maven.org\maven2\org\scala-sbt\sbt\1.3.2\sbt-1.3.2.pom (expected SHA-1 4f8a5d7e2bf4c184d43ae9cc18466e23878ca5db in C:\temp\SSCCE\null\Coursier\cache\v1\https\repo1.maven.org\maven2\org\scala-sbt\sbt\1.3.2\.sbt-1.3.2.pom__sha1, got edf765410c981897fdce97c5629bbc0342509b43)</code>)</p>
  <p>I found discussion of using Ivy vs Coursier, so included the lines below</p>
  <pre><code>useCoursier := false
  update / checksums := Nil
  </code></pre>
  <p>This still didn't help, so after a little more searching, I cleared the project/null/Coursier/cache folder &amp; retried.  This allowed me to build &amp; run the tests, but all requests threw the exception <em>j.n.s.SSLException: failure when writing TLS control frames</em>, and I can now reliably switch between building &amp; getting the exception if I use Coursier, or building &amp; getting no exception if I use Ivy.  The project folder is not small, but I put together a <a href="http://sscce.org/" rel="nofollow noreferrer">SSCCE.org</a> <a href="https://drive.google.com/file/d/1cdcF_Gpv_MLIa8KHQelHQ02YyQ1OqE7v/view" rel="nofollow noreferrer">project to demonstrate this behaviour</a> should anyone please have time to offer thoughts.</p>