fix retrieving deps via sftp resolver

build.sbt

@@ -3,8 +3,8 @@ import Path._
 import com.typesafe.tools.mima.core._, ProblemFilters._
 
 val _ = {
+  //https://github.com/sbt/contraband/issues/122
   sys.props += ("line.separator" -> "\n")
-  sys.props += ("file.separaror" -> "/")
 }
 
 def commonSettings: Seq[Setting[_]] = Seq(

ivy/src/main/scala/sbt/internal/librarymanagement/ConvertResolver.scala

@@ -7,7 +7,7 @@ import java.net.URL
 import java.util.Collections
 
 import org.apache.ivy.core.module.descriptor.DependencyDescriptor
-import org.apache.ivy.core.resolve.ResolveData
+import org.apache.ivy.core.resolve.{ DownloadOptions, ResolveData }
 import org.apache.ivy.core.settings.IvySettings
 import org.apache.ivy.plugins.repository.{ RepositoryCopyProgressListener, Resource, TransferEvent }
 import org.apache.ivy.plugins.resolver.{
@@ -30,6 +30,7 @@ import java.io.{ File, IOException }
 
 import org.apache.ivy.util.{ ChecksumHelper, FileUtil, Message }
 import org.apache.ivy.core.module.descriptor.{ Artifact => IArtifact }
+import org.apache.ivy.core.report.DownloadReport
 import sbt.io.IO
 import sbt.util.Logger
 import sbt.librarymanagement._
@@ -181,7 +182,7 @@ private[sbt] object ConvertResolver {
           resolver
         }
         case repo: SshRepository => {
-          val resolver = new SshResolver with DescriptorRequired {
+          val resolver = new SshResolver with DescriptorRequired with ThreadSafeSshBasedResolver {
             override val managedChecksumsEnabled: Boolean = managedChecksums
             override def getResource(resource: Resource, dest: File): Long = get(resource, dest)
           }
@@ -190,7 +191,7 @@ private[sbt] object ConvertResolver {
           resolver
         }
         case repo: SftpRepository => {
-          val resolver = new SFTPResolver
+          val resolver = new SFTPResolver with ThreadSafeSshBasedResolver
           initializeSSHResolver(resolver, repo, settings)
           resolver
         }
@@ -406,4 +407,15 @@ private[sbt] object ConvertResolver {
       }
     }
   }
+
+  private sealed trait ThreadSafeSshBasedResolver
+      extends org.apache.ivy.plugins.resolver.AbstractSshBasedResolver {
+//uncomment to test non-threadsafe behavior
+//    private def lock = new Object
+    private val lock = org.apache.ivy.plugins.repository.ssh.SshCache.getInstance
+    override def download(artifacts: Array[IArtifact], options: DownloadOptions): DownloadReport =
+      lock.synchronized {
+        super.download(artifacts, options)
+      }
+  }
 }

ivy/src/test/scala/sbt/internal/librarymanagement/SftpRepoSpec.scala

@@ -0,0 +1,42 @@
+package sbt.internal.librarymanagement
+
+import sbt.io._
+import sbt.io.syntax._
+import sbt.util.Level
+import sbt.librarymanagement._
+import sbt.librarymanagement.syntax._
+import java.nio.file.Paths
+
+//by default this test is ignored
+//to run this you need to change "repo" to point to some sftp repository which contains a dependency referring a dependency in same repo
+//it will then attempt to authenticate via key file and fetch the dependency specified via "org" and "module"
+class SftpRepoSpec extends BaseIvySpecification {
+  val repo: Option[String] = None
+//  val repo: Option[String] = Some("some repo")
+  //a dependency which depends on another in the repo
+  def org(repo: String) = s"com.${repo}"
+  def module(org: String) = org % "some-lib" % "version"
+
+  override def resolvers = {
+    implicit val patterns = Resolver.defaultIvyPatterns
+    repo.map { repo =>
+      val privateKeyFile = Paths.get(sys.env("HOME"), ".ssh", s"id_${repo}").toFile
+      Resolver.sftp(repo, s"repo.${repo}.com", 2222).as(repo, privateKeyFile)
+    }.toVector ++ super.resolvers
+  }
+
+  "resolving multiple deps from sftp repo" should "not hang or fail" in {
+    repo match {
+      case Some(repo) =>
+        IO.delete(currentTarget / "cache" / org(repo))
+        //    log.setLevel(Level.Debug)
+        lmEngine().retrieve(module(org(repo)), scalaModuleInfo = None, currentTarget, log) match {
+          case Right(v) => log.debug(v.toString())
+          case Left(e) =>
+            log.log(Level.Error, e.failedPaths.toString())
+            throw e.resolveException
+        }
+      case None => log.info(s"skipped ${getClass}")
+    }
+  }
+}