Revert "[2.x] fix: Skip Conflict when dependency relocations form a cycle (#8919)"

This reverts commit b24ecddbd6.

lm-coursier/src/main/scala/lmcoursier/internal/RelocationCycleDetector.scala

@@ -1,70 +0,0 @@
-package lmcoursier.internal
-
-import coursier.core.*
-import coursier.core.Resolution as CoreResolution
-import coursier.{ Dependency, Resolution }
-
-import scala.annotation.tailrec
-
-/**
- * Detects cyclic Maven / Gradle relocation chains that make
- * `coursier.graph.DependencyTree` loop forever (see sbt#8917, coursier#3578).
- *
- * Mirrors one step of `coursier.graph.DependencyTree.Node.relocation` so we
- * only skip `Conflict` when Coursier would spin on the same graph.
- */
-private[internal] object RelocationCycleDetector:
-
-  type Mvc = CoreResolution.ModuleVersionConstraint
-
-  private def oneRelocationStep(resolution: Resolution, dep: Dependency): Option[Mvc] =
-    resolution.reconciledVersions
-      .get(dep.module)
-      .flatMap: recon =>
-        val dep0 =
-          if dep.versionConstraint == recon then dep
-          else dep.withVersionConstraint(recon)
-        resolution.projectCache0
-          .get(dep0.moduleVersionConstraint)
-          .flatMap:
-            case (_, proj) =>
-              val mavenRelocatedOpt =
-                if proj.relocated && proj.dependencies0.lengthCompare(1) == 0 then
-                  Some(proj.dependencies0.head._2)
-                else None
-              def gradleRelocated: Option[Dependency] =
-                dep0.variantSelector match
-                  case attr: VariantSelector.AttributesBased =>
-                    if proj.variants.isEmpty then None
-                    else
-                      proj.variantFor(attr) match
-                        case Left(_)        => None
-                        case Right(variant) => proj.isRelocatedVariant(variant)
-                  case _: VariantSelector.ConfigurationBased => None
-              mavenRelocatedOpt
-                .orElse(gradleRelocated)
-                .map: relocatedTo =>
-                  val relocatedTo0 =
-                    if relocatedTo.variantSelector.isEmpty then
-                      relocatedTo.withVariantSelector(dep0.variantSelector)
-                    else relocatedTo
-                  relocatedTo0.moduleVersionConstraint
-
-  /** When true, `coursier.graph.Conflict(resolution)` can run indefinitely. */
-  def hasRelocationCycle(resolution: Resolution): Boolean =
-    resolution.isDone && resolution.conflicts.isEmpty && resolution.errors0.isEmpty && {
-      val keys = resolution.projectCache0.keySet
-      keys.exists: start =>
-        @tailrec
-        def walk(visited: Set[Mvc], cur: Option[Mvc]): Boolean =
-          cur match
-            case None => false
-            case Some(mvc) =>
-              if visited.contains(mvc) then true
-              else
-                val dep = Dependency(module = mvc._1, version = mvc._2)
-                walk(visited + mvc, oneRelocationStep(resolution, dep))
-        walk(Set.empty, Some(start))
-    }
-
-end RelocationCycleDetector

lm-coursier/src/main/scala/lmcoursier/internal/SbtUpdateReport.scala

@@ -361,22 +361,6 @@ private[internal] object SbtUpdateReport {
       classLoaders: Seq[ClassLoader],
   ): UpdateReport = {
 
-    val skipConflictDetail: Map[Configuration, Boolean] =
-      resolutions.map { case (cfg, subRes) =>
-        cfg -> RelocationCycleDetector.hasRelocationCycle(subRes)
-      }.toMap
-    val configsWithRelocationCycle =
-      skipConflictDetail.collect { case (cfg, true) => cfg.value }.toSeq.sorted
-    if (configsWithRelocationCycle.nonEmpty) {
-      log.warn(
-        "Skipping dependency conflict detail for configuration(s) " +
-          configsWithRelocationCycle.mkString(", ") +
-          ": cyclic Maven or Gradle relocations in the resolved graph. " +
-          "Resolution succeeded; eviction detail may be incomplete. " +
-          "See https://github.com/sbt/sbt/issues/8917"
-      )
-    }
-
     val configReports = resolutions.map { (config, subRes) =>
       val reports = moduleReports(
         thisModule,
@@ -412,9 +396,7 @@ private[internal] object SbtUpdateReport {
       }
 
       def conflicts: Seq[coursier.graph.Conflict] =
-        try
-          if (skipConflictDetail.getOrElse(config, false)) Nil
-          else coursier.graph.Conflict(subRes)
+        try coursier.graph.Conflict(subRes)
         catch case e: Throwable if missingOk => Nil
       val evicted = for {
         c <- conflicts

lm-coursier/src/test/scala/lmcoursier/internal/RelocationCycleDetectorSpec.scala

@@ -1,10 +0,0 @@
-package lmcoursier.internal
-
-import coursier.Resolution
-import org.scalatest.funsuite.AnyFunSuite
-import org.scalatest.matchers.should.Matchers
-
-class RelocationCycleDetectorSpec extends AnyFunSuite with Matchers:
-
-  test("incomplete resolution is not treated as having a relocation cycle"):
-    RelocationCycleDetector.hasRelocationCycle(Resolution()) shouldBe false