title: Why does the sbt tutorial fail on adding the plugin?
body: <p>I'm working thru the sbt introductory tutorial at <a href="https://www.scala-sbt.org/1.x/docs/sbt-by-example.html" rel="nofollow noreferrer">https://www.scala-sbt.org/1.x/docs/sbt-by-example.html</a> and when I reload after the step "Add sbt-native-packager plugin" which adds a plugin, it fails, with many warnings and errors, to a prompt of "Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore?"  At that point sbt has basically died.  I will append a full capture of the errors.  </p>
  
  <p>I believe I followed all instructions.  What is going wrong?</p>
  
  <p>I have tried:</p>
  
  <ul>
  <li>Restarting sbt</li>
  <li>Undoing the latest code the tutorial asked for (plugins.sbt and changes in build.sbt) and restarting sbt.  Then sbt is live again, but of course as soon as I add the code back it dies again.</li>
  <li><p>Adding resolvers for other repos that I know of, </p>
  
  <ul>
  <li>The built-in resolvers mentioned in <a href="https://www.scala-sbt.org/1.x/docs/Resolvers.html" rel="nofollow noreferrer">https://www.scala-sbt.org/1.x/docs/Resolvers.html</a></li>
  <li>resolvers += "apache-repo" at "<a href="https://repo.maven.apache.org/maven2/com/typesafe/" rel="nofollow noreferrer">https://repo.maven.apache.org/maven2/com/typesafe/</a>"</li>
  <li><p>resolvers += "lightbend" at "<a href="https://repo.lightbend.com/typesafe/releases/" rel="nofollow noreferrer">https://repo.lightbend.com/typesafe/releases/</a>"</p></li>
  <li><p>resolvers += "lightbend" at "<a href="https://repo.lightbend.com/typesafe/ivy-releases/" rel="nofollow noreferrer">https://repo.lightbend.com/typesafe/ivy-releases/</a>"</p></li>
  </ul></li>
  <li>Totally replacing the "resolvers" variable in case an early one was poisoning the process.  </li>
  <li>Changing the requested version from "1.3.4" to other versions of sbt-native-
  packager that I know exist.  Basically the same story with different version numbers.</li>
  </ul>
  
  <p>As I am new to Scala and sbt, I may be missing something elementary, but I'm just not seeing it.</p>
  
  <p>Here is the complete error log:</p>
  
  <pre><code>[info] Loading settings for project foo-build-build from plugins.sbt ...
  [info] Loading project definition from /home/tehom/projects/ic-fab/foo-build/project
  [warn] 
  [warn]  Note: Some unresolved dependencies have extra attributes.  Check that these dependencies exist with the requested attributes.
  [warn]      com.typesafe.sbt:sbt-native-packager:1.3.4 (sbtVersion=1.0, scalaVersion=2.12)
  [warn] 
  [warn]  Note: Unresolved dependencies path:
  [error] sbt.librarymanagement.ResolveException: Error downloading com.typesafe.sbt:sbt-native-packager;sbtVersion=1.0;scalaVersion=2.12:1.3.4
  [error]   Not found
  [error]   Not found
  [error]   not found: https://repo1.maven.org/maven2/com/typesafe/sbt/sbt-native-packager_2.12_1.0/1.3.4/sbt-native-packager-1.3.4.pom
  [error]   not found: /home/tehom/.ivy2/local/com.typesafe.sbt/sbt-native-packager/scala_2.12/sbt_1.0/1.3.4/ivys/ivy.xml
  [error]   download error: Caught javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target (PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target) while downloading https://repo.scala-sbt.org/scalasbt/sbt-plugin-releases/com.typesafe.sbt/sbt-native-packager/scala_2.12/sbt_1.0/1.3.4/ivys/ivy.xml
  [error]   download error: Caught javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target (PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target) while downloading https://repo.typesafe.com/typesafe/ivy-releases/com.typesafe.sbt/sbt-native-packager/scala_2.12/sbt_1.0/1.3.4/ivys/ivy.xml
  [error]     at lmcoursier.CoursierDependencyResolution.unresolvedWarningOrThrow(CoursierDependencyResolution.scala:246)
  [error]     at lmcoursier.CoursierDependencyResolution.$anonfun$update$34(CoursierDependencyResolution.scala:215)
  [error]     at scala.util.Either$LeftProjection.map(Either.scala:573)
  [error]     at lmcoursier.CoursierDependencyResolution.update(CoursierDependencyResolution.scala:215)
  [error]     at sbt.librarymanagement.DependencyResolution.update(DependencyResolution.scala:60)
  [error]     at sbt.internal.LibraryManagement$.resolve$1(LibraryManagement.scala:52)
  [error]     at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$12(LibraryManagement.scala:102)
  [error]     at sbt.util.Tracked$.$anonfun$lastOutput$1(Tracked.scala:69)
  [error]     at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$20(LibraryManagement.scala:115)
  [error]     at scala.util.control.Exception$Catch.apply(Exception.scala:228)
  [error]     at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$11(LibraryManagement.scala:115)
  [error]     at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$11$adapted(LibraryManagement.scala:96)
  [error]     at sbt.util.Tracked$.$anonfun$inputChanged$1(Tracked.scala:150)
  [error]     at sbt.internal.LibraryManagement$.cachedUpdate(LibraryManagement.scala:129)
  [error]     at sbt.Classpaths$.$anonfun$updateTask0$5(Defaults.scala:2947)
  [error]     at scala.Function1.$anonfun$compose$1(Function1.scala:49)
  [error]     at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62)
  [error]     at sbt.std.Transform$$anon$4.work(Transform.scala:67)
  [error]     at sbt.Execute.$anonfun$submit$2(Execute.scala:281)
  [error]     at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19)
  [error]     at sbt.Execute.work(Execute.scala:290)
  [error]     at sbt.Execute.$anonfun$submit$1(Execute.scala:281)
  [error]     at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178)
  [error]     at sbt.CompletionService$$anon$2.call(CompletionService.scala:37)
  [error]     at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
  [error]     at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
  [error]     at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
  [error]     at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
  [error]     at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
  [error]     at java.base/java.lang.Thread.run(Thread.java:834)
  [error] (update) sbt.librarymanagement.ResolveException: Error downloading com.typesafe.sbt:sbt-native-packager;sbtVersion=1.0;scalaVersion=2.12:1.3.4
  [error]   Not found
  [error]   Not found
  [error]   not found: https://repo1.maven.org/maven2/com/typesafe/sbt/sbt-native-packager_2.12_1.0/1.3.4/sbt-native-packager-1.3.4.pom
  [error]   not found: /home/tehom/.ivy2/local/com.typesafe.sbt/sbt-native-packager/scala_2.12/sbt_1.0/1.3.4/ivys/ivy.xml
  [error]   download error: Caught javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target (PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target) while downloading https://repo.scala-sbt.org/scalasbt/sbt-plugin-releases/com.typesafe.sbt/sbt-native-packager/scala_2.12/sbt_1.0/1.3.4/ivys/ivy.xml
  [error]   download error: Caught javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target (PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target) while downloading https://repo.typesafe.com/typesafe/ivy-releases/com.typesafe.sbt/sbt-native-packager/scala_2.12/sbt_1.0/1.3.4/ivys/ivy.xml
  Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore? q
  
  </code></pre>