This is a Pickling workaround so we can generate Scala docs

ivy/src/main/scala/sbt/Artifact.scala

@@ -80,6 +80,8 @@ object Artifact {
   private val stringStringMapPickler = implicitly[Pickler[Map[String, String]]]
   private val stringStringMapUnpickler = implicitly[Unpickler[Map[String, String]]]
 
+  implicit def fasttypetag[A]: FastTypeTag[A] = ???
+
   implicit val pickler: Pickler[Artifact] = new Pickler[Artifact] {
     val tag = implicitly[FastTypeTag[Artifact]]
     val stringTag = implicitly[FastTypeTag[String]]

ivy/src/main/scala/sbt/CrossVersion.scala

@@ -9,6 +9,8 @@ final case class ScalaVersion(full: String, binary: String)
 sealed trait CrossVersion
 
 object CrossVersion {
+  implicit def fasttypetag[A]: FastTypeTag[A] = ???
+
   /** The first `major.minor` Scala version that the Scala binary version should be used for cross-versioning instead of the full version. */
   val TransitionScalaVersion = CrossVersionUtil.TransitionScalaVersion
 

ivy/src/main/scala/sbt/JsonUtil.scala

@@ -79,10 +79,14 @@ private[sbt] object JsonUtil {
 
 private[sbt] case class UpdateReportLite(configurations: Seq[ConfigurationReportLite])
 private[sbt] object UpdateReportLite {
+  implicit def fasttypetag[A]: FastTypeTag[A] = ???
+
   implicit val pickler: Pickler[UpdateReportLite] with Unpickler[UpdateReportLite] = PicklerUnpickler.generate[UpdateReportLite]
 }
 
 private[sbt] case class ConfigurationReportLite(configuration: String, details: Seq[OrganizationArtifactReport])
 private[sbt] object ConfigurationReportLite {
+  implicit def fasttypetag[A]: FastTypeTag[A] = ???
+
   implicit val pickler: Pickler[ConfigurationReportLite] with Unpickler[ConfigurationReportLite] = PicklerUnpickler.generate[ConfigurationReportLite]
 }

ivy/src/main/scala/sbt/ModuleID.scala

@@ -120,6 +120,8 @@ final case class ModuleID(organization: String, name: String, revision: String,
   def jar() = artifacts(Artifact(name))
 }
 object ModuleID {
+  implicit def fasttypetag[A]: FastTypeTag[A] = ???
+
   implicit val pickler: Pickler[ModuleID] with Unpickler[ModuleID] = PicklerUnpickler.generate[ModuleID]
 
   /** Prefixes all keys with `e:` if they are not already so prefixed. */

ivy/src/main/scala/sbt/UpdateReport.scala

@@ -44,6 +44,7 @@ final class ConfigurationReport(
     new ConfigurationReport(configuration, modules map { _.retrieve((mid, art, file) => f(configuration, mid, art, file)) }, details, evicted)
 }
 object ConfigurationReport {
+  implicit def fasttypetag[A]: FastTypeTag[A] = ???
   implicit val pickler: Pickler[ConfigurationReport] with Unpickler[ConfigurationReport] = PicklerUnpickler.generate[ConfigurationReport]
 }
 
@@ -68,6 +69,7 @@ final class OrganizationArtifactReport private[sbt] (
   }
 }
 object OrganizationArtifactReport {
+  implicit def fasttypetag[A]: FastTypeTag[A] = ???
   implicit val pickler: Pickler[OrganizationArtifactReport] with Unpickler[OrganizationArtifactReport] = PicklerUnpickler.generate[OrganizationArtifactReport]
 
   def apply(organization: String, name: String, modules: Seq[ModuleReport]): OrganizationArtifactReport =
@@ -162,6 +164,8 @@ final class ModuleReport(
 }
 
 object ModuleReport {
+  implicit def fasttypetag[A]: FastTypeTag[A] = ???
+
   def apply(module: ModuleID, artifacts: Seq[(Artifact, File)], missingArtifacts: Seq[Artifact]): ModuleReport =
     new ModuleReport(module, artifacts, missingArtifacts, None, None, None, None,
       false, None, None, None, None, Map(), None, None, Nil, Nil, Nil)
@@ -233,6 +237,8 @@ final class UpdateReport(val cachedDescriptor: File, val configurations: Seq[Con
 }
 
 object UpdateReport {
+  implicit def fasttypetag[A]: FastTypeTag[A] = ???
+
   implicit def richUpdateReport(report: UpdateReport): RichUpdateReport = new RichUpdateReport(report)
 
   /** Provides extra methods for filtering the contents of an `UpdateReport` and for obtaining references to a selected subset of the underlying files. */