Add withAddedResolvers to DependencyResolutionInterface

core/src/main/scala/sbt/librarymanagement/DependencyResolution.scala

@@ -198,6 +198,18 @@ class DependencyResolution private[sbt] (lmEngine: DependencyResolutionInterface
     }
   }
 
+  /**
+   * Returns a new copy of DependencyResolutionInterface which contains the added resolvers.
+   * Useful for when you have resolvers that are outside the context of an sbt scope/project
+   * (i.e. a standalone setting)
+   *
+   * @param resolvers The resolvers to add
+   * @param log       The logger
+   * @return A copy of DependencyResolutionInterface which contains the added resolvers
+   */
+  def withAddedResolvers(resolvers: Seq[Resolver], log: Logger): DependencyResolutionInterface =
+    lmEngine.withAddedResolvers(resolvers, log)
+
   protected def directDependenciesNames(module: ModuleDescriptor): String =
     (module.directDependencies map { case mID: ModuleID =>
       import mID._

core/src/main/scala/sbt/librarymanagement/LibraryManagementInterface.scala

@@ -32,6 +32,16 @@ trait DependencyResolutionInterface {
       uwconfig: UnresolvedWarningConfiguration,
       log: Logger
   ): Either[UnresolvedWarning, UpdateReport]
+
+  /**
+   * Returns a new copy of DependencyResolutionInterface which contains the added resolvers.
+   * Useful for when you have resolvers that are outside the context of an sbt scope/project
+   * (i.e. a standalone setting)
+   * @param resolvers The resolvers to add
+   * @param log The logger
+   * @return A copy of DependencyResolutionInterface which contains the added resolvers
+   */
+  def withAddedResolvers(resolvers: Seq[Resolver], log: Logger): DependencyResolutionInterface
 }
 
 /**

ivy/src/main/scala/sbt/librarymanagement/ivy/IvyDependencyResolution.scala

@@ -21,6 +21,19 @@ class IvyDependencyResolution private[sbt] (val ivySbt: IvySbt)
   ): Either[UnresolvedWarning, UpdateReport] =
     IvyActions.updateEither(toModule(module), configuration, uwconfig, log)
 
+  override def withAddedResolvers(
+      resolvers: Seq[Resolver],
+      log: Logger
+  ): IvyDependencyResolution = {
+    val newConfiguration = ivySbt.configuration match {
+      case configuration: ExternalIvyConfiguration =>
+        configuration.withExtraResolvers(configuration.extraResolvers ++ resolvers)
+      case configuration: InlineIvyConfiguration =>
+        configuration.withResolvers(configuration.resolvers ++ resolvers)
+    }
+    new IvyDependencyResolution(new IvySbt(newConfiguration))
+  }
+
   private[sbt] def toModule(module: ModuleDescriptor): Module =
     module match {
       case m: Module @unchecked => m