got 3.5 compiling using a shim

build.sbt

@@ -116,7 +116,7 @@ lazy val spark = (project in file("spark"))
       "org.apache.spark" %% "spark-sql" % sparkVersion % "test" classifier "tests",
       "org.apache.spark" %% "spark-hive" % sparkVersion % "test" classifier "tests",
     ),
-    Compile / unmanagedSourceDirectories := Seq((baseDirectory in Compile).value, "src", "shim-spark-3.5"),
+    Compile / unmanagedSourceDirectories ++= Seq((baseDirectory in Compile).value / "src" / "shim-spark-3.5"),
     // For adding staged Spark RC versions, Ex:
     // resolvers += "Apche Spark 3.5.0 (RC1) Staging" at "https://repository.apache.org/content/repositories/orgapachespark-1444/",
     Compile / packageBin / mappings := (Compile / packageBin / mappings).value ++

spark/src/main/scala/io/delta/tables/execution/VacuumTableCommand.scala

@@ -29,6 +29,8 @@ import org.apache.spark.sql.delta.commands.VacuumCommand.getDeltaTable
 import org.apache.spark.sql.execution.command.{LeafRunnableCommand, RunnableCommand}
 import org.apache.spark.sql.types.StringType
 
+import foo.bar.UnresolvedTableShim
+
 /**
  * The `vacuum` command implementation for Spark SQL. Example SQL:
  * {{{
@@ -77,7 +79,8 @@ object VacuumTableCommand {
       dryRun: Boolean): VacuumTableCommand = {
     val child = UnresolvedDeltaPathOrIdentifier(path, table, "VACUUM")
     val unresolvedInventoryTable = inventoryTable.map(rt =>
-      UnresolvedTableShim.createUnresolvedTable(rt.nameParts, "VACUUM", relationTypeMismatchHint = None))
+      UnresolvedTableShim.createUnresolvedTable(
+        rt.nameParts, "VACUUM", relationTypeMismatchHint = None))
     VacuumTableCommand(child, horizonHours, unresolvedInventoryTable, inventoryQuery, dryRun)
   }
 }

spark/src/shim-spark-3.5/UnresolvedTableShim.scala

@@ -1,10 +1,28 @@
+/*
+ * Copyright (2021) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package foo.bar
+
 import org.apache.spark.sql.catalyst.analysis.UnresolvedTable
 
 object UnresolvedTableShim {
   def createUnresolvedTable(
       tableNameParts: Seq[String],
       commandName: String,
-      relationTypeMismatchHint: Option[String] = None) = {
+      relationTypeMismatchHint: Option[String] = None): UnresolvedTable = {
     UnresolvedTable(tableNameParts, commandName, relationTypeMismatchHint)
   }
-}
+}

spark/src/shim-spark-4.0/UnresolvedTableShim.scala

@@ -1,10 +1,26 @@
+/*
+ * Copyright (2021) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 import org.apache.spark.sql.catalyst.analysis.UnresolvedTable
 
 object UnresolvedTableShim {
   def createUnresolvedTable(
       tableNameParts: Seq[String],
       commandName: String,
-      relationTypeMismatchHint: Option[String] = None) = {
+      relationTypeMismatchHint: Option[String] = None): UnresolvedTable = {
     UnresolvedTable(tableNameParts, commandName)
   }
-}
+}