diff --git a/main/src/main/java/sbt/internal/XMainConfiguration.java b/main/src/main/java/sbt/internal/XMainConfiguration.java
index d6cf69af2..674d39008 100644
--- a/main/src/main/java/sbt/internal/XMainConfiguration.java
+++ b/main/src/main/java/sbt/internal/XMainConfiguration.java
@@ -8,10 +8,14 @@
 package sbt.internal;
 
 import java.io.File;
+import java.io.IOException;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.net.MalformedURLException;
 import java.net.URL;
+import java.net.URLConnection;
+import java.nio.file.Paths;
 import xsbti.*;
 
 /**
@@ -25,6 +29,10 @@ public class XMainConfiguration {
   public xsbti.MainResult run(String moduleName, xsbti.AppConfiguration configuration)
       throws Throwable {
     try {
+      boolean isScripted = Boolean.parseBoolean(System.getProperty("sbt.scripted"));
+      // in batch scripted tests, we disable caching of JAR URL connections to avoid interference
+      // between tests
+      if (isScripted) disableCachingOfURLConnections();
       ClassLoader topLoader = configuration.provider().scalaProvider().launcher().topLoader();
       xsbti.AppConfiguration updatedConfiguration = null;
       try {
@@ -56,7 +64,7 @@ public class XMainConfiguration {
         clw.getMethod("warmup").invoke(clw.getField("MODULE$").get(null));
         return (xsbti.MainResult) runMethod.invoke(instance, updatedConfiguration);
       } catch (InvocationTargetException e) {
-        // This propogates xsbti.FullReload to the launcher
+        // This propagates xsbti.FullReload to the launcher
         throw e.getCause();
       }
     } catch (ReflectiveOperationException e) {
@@ -104,6 +112,22 @@ public class XMainConfiguration {
     }
   }
 
+  private class FakeURLConnection extends URLConnection {
+    public FakeURLConnection(URL url) {
+      super(url);
+    }
+
+    public void connect() throws IOException {}
+  }
+
+  private void disableCachingOfURLConnections() {
+    try {
+      URLConnection conn = new FakeURLConnection(Paths.get(".").toUri().toURL());
+      conn.setDefaultUseCaches(false);
+    } catch (MalformedURLException e) {
+    }
+  }
+
   /*
    * Replaces the AppProvider.loader method with a new loader that puts the sbt test interface
    * jar ahead of the rest of the sbt classpath in the classloading hierarchy.
diff --git a/main/src/main/scala/sbt/EvaluateTask.scala b/main/src/main/scala/sbt/EvaluateTask.scala
index 8c8f42a66..06e5b9105 100644
--- a/main/src/main/scala/sbt/EvaluateTask.scala
+++ b/main/src/main/scala/sbt/EvaluateTask.scala
@@ -337,10 +337,9 @@ object EvaluateTask {
 
   def evalPluginDef(pluginDef: BuildStructure, state: State): PluginData = {
     val root = ProjectRef(pluginDef.root, Load.getRootProject(pluginDef.units)(pluginDef.root))
-    val pluginKey = pluginData
     val config = extractedTaskConfig(Project.extract(state), pluginDef, state)
     val evaluated =
-      apply(pluginDef, ScopedKey(pluginKey.scope, pluginKey.key), state, root, config)
+      apply(pluginDef, ScopedKey(pluginData.scope, pluginData.key), state, root, config)
     val (newS, result) = evaluated getOrElse sys.error(
       "Plugin data does not exist for plugin definition at " + pluginDef.root
     )
diff --git a/main/src/main/scala/sbt/internal/PluginDiscovery.scala b/main/src/main/scala/sbt/internal/PluginDiscovery.scala
index 79f3aba11..35afdd3fb 100644
--- a/main/src/main/scala/sbt/internal/PluginDiscovery.scala
+++ b/main/src/main/scala/sbt/internal/PluginDiscovery.scala
@@ -136,9 +136,10 @@ object PluginDiscovery:
       .getResources(resourceName)
       .asScala
       .toSeq
-      .filter(onClasspath(classpath, converter)) flatMap { u =>
-      IO.readLinesURL(u).map(_.trim).filter(!_.isEmpty)
-    }
+      .filter(onClasspath(classpath, converter))
+      .flatMap { u =>
+        IO.readLinesURL(u).map(_.trim).filter(!_.isEmpty)
+      }
 
   /** Returns `true` if `url` is an entry in `classpath`. */
   def onClasspath(classpath: Def.Classpath, converter: FileConverter)(url: URL): Boolean =