diff --git a/.jvmopts b/.jvmopts
index dc0787730..d2ce8b88e 100644
--- a/.jvmopts
+++ b/.jvmopts
@@ -1,3 +1 @@
 -Xmx12g
--XX:+CMSClassUnloadingEnabled
--XX:+UseConcMarkSweepGC
diff --git a/compile.sbt b/compile.sbt
index de5e70e0e..153ca5e1c 100644
--- a/compile.sbt
+++ b/compile.sbt
@@ -1,4 +1,4 @@
-import org.clulab.sbt.Versioner
+//import org.clulab.sbt.Versioner
 
 // This setting adversely affects logLevel during tests, so needs counterweight.
 // ThisBuild / Compile / logLevel := Level.Error
@@ -6,7 +6,7 @@ import org.clulab.sbt.Versioner
 ThisBuild / Compile / scalacOptions ++= Seq("-feature", "-unchecked", "-deprecation")
 Compile / sourceGenerators += Def.task {
   import java.io.File
-  import Versioner._
+  //import Versioner._
   // These values need to be collected in a task in order have them forwarded to Scala functions.
   val versioner = Versioner(git.runner.value, git.gitCurrentBranch.value, baseDirectory.value, (Compile / sourceManaged).value)
 
diff --git a/eidoscommon/build.sbt b/eidoscommon/build.sbt
index 4bf9a167d..cd29c50e3 100644
--- a/eidoscommon/build.sbt
+++ b/eidoscommon/build.sbt
@@ -10,8 +10,8 @@ resolvers ++= Seq(
 
 libraryDependencies ++= {
   // Versions were last checked 2021 Mar 12.
-  val procVer = "8.5.0"
-  val luceneVer = "6.6.6"
+  val procVer = "8.5.2-SNAPSHOT"
+  val luceneVer = "7.5.0" // Match processors!
 
   // Run dependencyTree, dependencyList, and dependencyStats on eidos and
   // see what kinds of duplicates with different version numbers show up.
@@ -21,6 +21,7 @@ libraryDependencies ++= {
     // It is possible then that something using eidoscommons and something using
     // eidos would get different answers.
     "org.apache.lucene"           % "lucene-analyzers-common"  % luceneVer,
+    "org.apache.lucene"           % "lucene-backward-codecs"   % luceneVer,
     "org.apache.lucene"           % "lucene-core"              % luceneVer,
     "org.apache.lucene"           % "lucene-queries"           % luceneVer,
     "org.apache.lucene"           % "lucene-queryparser"       % luceneVer,
diff --git a/eidoscommon/src/main/scala/org/clulab/wm/eidoscommon/utils/Closer.scala b/eidoscommon/src/main/scala/org/clulab/wm/eidoscommon/utils/Closer.scala
index 94dc57942..89c817a41 100644
--- a/eidoscommon/src/main/scala/org/clulab/wm/eidoscommon/utils/Closer.scala
+++ b/eidoscommon/src/main/scala/org/clulab/wm/eidoscommon/utils/Closer.scala
@@ -1,20 +1,41 @@
 package org.clulab.wm.eidoscommon.utils
 
-import scala.language.reflectiveCalls
+import scala.io.Source
+import scala.language.implicitConversions
 import scala.util.control.NonFatal
 
 object Closer {
 
-  protected type Closeable = {def close() : Unit}
+  trait Releasable[Resource] {
+    def release(resource: Resource): Unit
+  }
+
+  object Releasable {
+
+    implicit def releasableAutoCloseable[Resource <: AutoCloseable]: Releasable[Resource] = {
+      new Releasable[Resource] {
+        def release(resource: Resource): Unit = resource.close()
+      }
+    }
 
-  def close[Resource <: Closeable](resource: => Resource): Unit = resource.close()
+    // In Scala 2.11, Source does not inherit from Closeable, so one has to tell Closer how to close() it.
+    implicit def releasableSource[Resource <: Source]: Releasable[Resource] = {
+      new Releasable[Resource] {
+        def release(resource: Resource): Unit = resource.close()
+      }
+    }
+  }
+
+  def close[Resource: Releasable](resource: => Resource): Unit =
+      implicitly[Releasable[Resource]].release(resource)
 
   // This is so that exceptions caused during close are caught, but don't
   // prevent the registration of any previous exception.
   // See also https://medium.com/@dkomanov/scala-try-with-resources-735baad0fd7d.
   // Others have resource: => Closeable, but I want the resource evaluated beforehand
   // so that it doesn't throw an exception before there is anything to close.
-  def autoClose[Resource <: Closeable, Result](resource: Resource)(function: Resource => Result): Result = {
+  // 3 here is for the number of arguments.  Operator overloading doesn't handle it.
+  protected def autoClose3[Resource, Result](resource: Resource)(closer: () => Unit)(function: Resource => Result): Result = {
 
     val (result: Option[Result], exception: Option[Throwable]) = try {
       (Some(function(resource)), None)
@@ -23,9 +44,9 @@ object Closer {
       case exception: Throwable => (None, Some(exception))
     }
 
-    val closeException: Option[Throwable] = Option(resource).flatMap { resource =>
+    val closeException: Option[Throwable] = Option(resource).flatMap { _ =>
       try {
-        resource.close()
+        closer()
         None
       }
       catch {
@@ -54,9 +75,12 @@ object Closer {
     }
   }
 
-  // Allow for alternative syntax closeable.autoClose { closeable => ... }
-  implicit class AutoCloser[Resource <: Closer.Closeable](resource: Resource) {
+  def autoClose[Resource: Releasable, Result](resource: Resource)(function: Resource => Result): Result =
+      autoClose3(resource)(() => implicitly[Releasable[Resource]].release(resource))(function)
+
+  implicit class AutoCloser[Resource: Releasable](resource: Resource) {
 
-    def autoClose[Result](function: Resource => Result): Result = Closer.autoClose(resource)(function)
+    def autoClose[Result](function: Resource => Result): Result =
+        Closer.autoClose(resource)(function)
   }
 }
diff --git a/eidoscommon/src/main/scala/org/clulab/wm/eidoscommon/utils/XsvUtils.scala b/eidoscommon/src/main/scala/org/clulab/wm/eidoscommon/utils/XsvUtils.scala
index f3c84929e..7e8c17bbf 100644
--- a/eidoscommon/src/main/scala/org/clulab/wm/eidoscommon/utils/XsvUtils.scala
+++ b/eidoscommon/src/main/scala/org/clulab/wm/eidoscommon/utils/XsvUtils.scala
@@ -1,6 +1,6 @@
 package org.clulab.wm.eidoscommon.utils
 
-import java.io.PrintWriter
+import java.io.{Closeable, PrintWriter}
 
 class EscapePair(char: Char, escaped: Char) {
   val unescapedString: String = char.toString
@@ -74,7 +74,7 @@ class CsvReader() extends XsvReader(XsvUtils.commaChar) {
   // TODO It is more complicated because of the multiple lines per string
 }
 
-abstract class XsvWriter(val printWriter: PrintWriter, separatorChar: Char) {
+abstract class XsvWriter(val printWriter: PrintWriter, separatorChar: Char) extends Closeable {
   protected val separatorString: String = separatorChar.toString
 
   def quote(text: String): String = "\"" + text.replace("\"", "\"\"") + "\""
diff --git a/eidoscommon/src/test/scala/org/clulab/wm/eidoscommon/utils/TestAutoClosing.scala b/eidoscommon/src/test/scala/org/clulab/wm/eidoscommon/utils/TestAutoClosing.scala
index 37bc26369..578f7f4c9 100644
--- a/eidoscommon/src/test/scala/org/clulab/wm/eidoscommon/utils/TestAutoClosing.scala
+++ b/eidoscommon/src/test/scala/org/clulab/wm/eidoscommon/utils/TestAutoClosing.scala
@@ -2,9 +2,12 @@ package org.clulab.wm.eidoscommon.utils
 
 import org.clulab.wm.eidoscommon.utils.Closer.AutoCloser
 
+import java.io.Closeable
+import scala.io.Source
+
 class TestAutoClosing extends Test {
 
-  class Closing(exception: Option[Throwable] = None) {
+  class Closing(exception: Option[Throwable] = None) extends Closeable {
     var closed: Boolean = false // test
 
     def close(): Unit = {
@@ -137,4 +140,9 @@ class TestAutoClosing extends Test {
     }
     closing.closed should be (false)
   }
+
+  it should "work with a plain Source, even in Scala 2.11" in {
+    val source = Source.fromString("foo\nbar\n")
+    Closer.close(source)
+  }
 }
diff --git a/eidoscommon/src/test/scala/org/clulab/wm/eidoscommon/utils/TestCloser.scala b/eidoscommon/src/test/scala/org/clulab/wm/eidoscommon/utils/TestCloser.scala
index e685926cd..16e46b2e7 100644
--- a/eidoscommon/src/test/scala/org/clulab/wm/eidoscommon/utils/TestCloser.scala
+++ b/eidoscommon/src/test/scala/org/clulab/wm/eidoscommon/utils/TestCloser.scala
@@ -1,8 +1,14 @@
 package org.clulab.wm.eidoscommon.utils
 
+
+import org.clulab.utils.Closer.AutoCloser
+
+import java.io.Closeable
+import scala.io.Source
+
 class TestCloser extends Test {
 
-  class Closing(exception: Option[Throwable] = None) {
+  class Closing(exception: Option[Throwable] = None) extends Closeable {
     var closed: Boolean = false // test
 
     def close(): Unit = {
@@ -135,4 +141,10 @@ class TestCloser extends Test {
     }
     closing.closed should be (false)
   }
+
+  it should "work with a plain Source, even in Scala 2.11" in {
+    Source.fromString("foo\nbar\n").autoClose { source =>
+      source.getLines.toList
+    }
+  }
 }
diff --git a/project/build.properties b/project/build.properties
index 495c3b551..507badd1e 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -4,4 +4,4 @@
 # Avoid "java.lang.OutOfMemoryError: Required array size too large" of 1.4+.
 # Versions in the 1.3+ range seem to break the sbt-dependency-graph plugin and ivy-related things.
 # Processors is at 1.2.8, the highest available 1.2.
-sbt.version = 1.4.5
+sbt.version = 1.6.2
diff --git a/src/test/scala/org/clulab/wm/eidos/text/englishGrounding/TestGrounding.scala b/src/test/scala/org/clulab/wm/eidos/text/englishGrounding/TestGrounding.scala
index 5020cb2cf..8d4131734 100644
--- a/src/test/scala/org/clulab/wm/eidos/text/englishGrounding/TestGrounding.scala
+++ b/src/test/scala/org/clulab/wm/eidos/text/englishGrounding/TestGrounding.scala
@@ -9,6 +9,8 @@ import org.clulab.wm.eidos.mentions.EidosMention
 import org.clulab.wm.eidos.test.EnglishGroundingTest
 import org.clulab.wm.eidos.test.TestUtils._
 
+import scala.language.reflectiveCalls
+
 class TestGrounding extends EnglishGroundingTest {
   // Grounding needs to be activated in englishTest.conf for these tests to be active.
   // Update: Grounding is now activated in EnglishTests by default.
diff --git a/wmexchanger/src/main/scala/org/clulab/wm/wmexchanger/utils/RestExchanger.scala b/wmexchanger/src/main/scala/org/clulab/wm/wmexchanger/utils/RestExchanger.scala
index 5d4ac8f26..4c7be5c9c 100644
--- a/wmexchanger/src/main/scala/org/clulab/wm/wmexchanger/utils/RestExchanger.scala
+++ b/wmexchanger/src/main/scala/org/clulab/wm/wmexchanger/utils/RestExchanger.scala
@@ -8,12 +8,13 @@ import org.apache.http.impl.client.BasicCredentialsProvider
 import org.apache.http.impl.client.CloseableHttpClient
 import org.apache.http.impl.client.HttpClientBuilder
 
+import java.io.Closeable
 import java.net.URL
 
 // See https://hc.apache.org/httpcomponents-client-ga/tutorial/html/authentication.html
 // and https://mkyong.com/java/apache-httpclient-basic-authentication-examples/
 // and https://stackoverflow.com/questions/2304663/apache-httpclient-making-multipart-form-post
-class RestExchanger(service: String, username: String, password: String) {
+class RestExchanger(service: String, username: String, password: String) extends Closeable {
   protected val url = new URL(service)
   protected val httpHost: HttpHost = newHttpHost(url)