local SyncVar implementation to deal with std lib deprecations

util/process/src/main/scala/sbt/ProcessImpl.scala

@@ -9,8 +9,6 @@ import java.io.{FilterInputStream, FilterOutputStream, PipedInputStream, PipedOu
 import java.io.{File, FileInputStream, FileOutputStream}
 import java.net.URL
 
-import scala.concurrent.SyncVar
-
 /** Runs provided code in a new Thread and returns the Thread instance. */
 private object Spawn
 {

util/process/src/main/scala/sbt/SyncVar.scala

@@ -0,0 +1,40 @@
+package sbt
+
+// minimal copy of scala.concurrent.SyncVar since that version deprecated put and unset
+private[sbt] final class SyncVar[A]
+{
+	private[this] var isDefined: Boolean = false
+	private[this] var value: Option[A] = None
+
+	/** Waits until a value is set and then gets it.  Does not clear the value */
+	def get: A = synchronized {
+		while (!isDefined) wait()
+		value.get
+	}
+
+	/** Waits until a value is set, gets it, and finally clears the value. */
+	def take(): A = synchronized {
+		try get finally unset()
+	}
+
+	/** Sets the value, whether or not it is currently defined. */
+	def set(x: A): Unit = synchronized {
+ 		isDefined = true
+		value = Some(x)
+		notifyAll()
+	}
+
+	/** Sets the value, first waiting until it is undefined if it is currently defined. */
+	def put(x: A): Unit = synchronized {
+		while (isDefined) wait()
+		set(x)
+	}
+
+	/** Clears the value, whether or not it is current defined. */
+	def unset(): Unit = synchronized {
+		isDefined = false
+		value = None
+		notifyAll()
+	}
+}
+