Deprecate -, --, and --- in favor of onFailure, sbtClearOnFailure, and resumeFromFailure.

main/command/src/main/scala/sbt/BasicCommandStrings.scala

@@ -113,8 +113,23 @@ AliasCommand + """ name=
 	def StashOnFailure = "sbtStashOnFailure"
 	def PopOnFailure = "sbtPopOnFailure"
 
-	def ClearOnFailure = "--"
+	// commands with poor choices for names since they clash with the usual conventions for command line options
-	def OnFailure = "-"
+	//   these are not documented and are mainly internal commands and can be removed without a full deprecation cycle
+	object Compat {
+		def OnFailure = "-"
+		def ClearOnFailure = "--"
+		def FailureWall = "---"
+		def OnFailureDeprecated = deprecatedAlias(OnFailure, BasicCommandStrings.OnFailure)
+		def ClearOnFailureDeprecated = deprecatedAlias(ClearOnFailure, BasicCommandStrings.ClearOnFailure)
+		def FailureWallDeprecated = deprecatedAlias(FailureWall, BasicCommandStrings.FailureWall)
+		private[this] def deprecatedAlias(oldName: String, newName: String): String =
+			s"The `$oldName` command is deprecated in favor of `$newName` and will be removed in 0.14.0"
+	}
+
+	def FailureWall = "resumeFromFailure"
+
+	def ClearOnFailure = "sbtClearOnFailure"
+	def OnFailure = "onFailure"
 	def OnFailureDetailed =
 OnFailure + """ command
 

main/command/src/main/scala/sbt/BasicCommands.scala

@@ -6,7 +6,6 @@ package sbt
 	import Types.{const,idFun}
 	import Function.tupled
 	import Command.applyEffect
-	import State.FailureWall
 	import HistoryCommands.{Start => HistoryPrefix}
 	import BasicCommandStrings._
 	import CommandUtil._
@@ -16,7 +15,7 @@ package sbt
 
 object BasicCommands
 {
-	lazy val allBasicCommands = Seq(nop, ignore, help, multi, ifLast, append, setOnFailure, clearOnFailure, stashOnFailure, popOnFailure, reboot, call, exit, continuous, history, shell, read, alias)
+	lazy val allBasicCommands = Seq(nop, ignore, help, multi, ifLast, append, setOnFailure, clearOnFailure, stashOnFailure, popOnFailure, reboot, call, exit, continuous, history, shell, read, alias) ++ compatCommands
 
 	def nop = Command.custom(s => success(() => s))
 	def ignore = Command.command(FailureWall)(idFun)
@@ -52,7 +51,7 @@ object BasicCommands
 
 	def multi = Command.custom(multiApplied, Help(Multi, MultiBrief, MultiDetailed) )
 
-	lazy val otherCommandParser = (s: State) => token(OptSpace ~> combinedLax(s, any.+) )
+	lazy val otherCommandParser = (s: State) => token(OptSpace ~> combinedLax(s, NotSpaceClass ~ any.*) )
 	def combinedLax(s: State, any: Parser[_]): Parser[String] =
 		matched(s.combinedParser | token(any, hide= const(true)))
 
@@ -66,6 +65,21 @@ object BasicCommands
 	def setOnFailure = Command(OnFailure, Help.more(OnFailure, OnFailureDetailed))(otherCommandParser) { (s, arg) =>
 		s.copy(onFailure = Some(arg))
 	}
+	private[sbt] def compatCommands = Seq(
+		Command.command(Compat.ClearOnFailure) { s =>
+			s.log.warn(Compat.ClearOnFailureDeprecated)
+			s.copy(onFailure = None)
+		},
+		Command.arb(s => token(Compat.OnFailure, hide = const(true)).flatMap(x => otherCommandParser(s)) ){ (s, arg) =>
+			s.log.warn(Compat.OnFailureDeprecated)
+			s.copy(onFailure = Some(arg))
+		},
+		Command.command(Compat.FailureWall) { s =>
+			s.log.warn(Compat.FailureWallDeprecated)
+			s
+		}
+	)
+
 	def clearOnFailure = Command.command(ClearOnFailure)(s => s.copy(onFailure = None))
 	def stashOnFailure = Command.command(StashOnFailure)(s => s.copy(onFailure = None).update(OnFailureStack)(s.onFailure :: _.toList.flatten))
 	def popOnFailure = Command.command(PopOnFailure) { s =>

main/command/src/main/scala/sbt/State.scala

@@ -130,7 +130,7 @@ trait StateOps {
 object State
 {
 	/** Indicates where command execution should resume after a failure.*/
-	final val FailureWall = "---"
+	val FailureWall = BasicCommandStrings.FailureWall
 
 	/** Represents the next action for the command processor.*/
 	sealed trait Next
@@ -199,7 +199,8 @@ object State
 		def handleError(t: Throwable): State = handleException(t, s, log)
 		def fail =
 		{
-			val remaining = s.remainingCommands.dropWhile(_ != FailureWall)
+				import BasicCommandStrings.Compat.{FailureWall => CompatFailureWall}
+			val remaining = s.remainingCommands.dropWhile(c => c != FailureWall && c != CompatFailureWall)
 			if(remaining.isEmpty)
 				applyOnFailure(s, Nil, exit(ok = false))
 			else

main/src/main/scala/sbt/Main.scala

@@ -85,7 +85,8 @@ object BuiltinCommands
 	def DefaultCommands: Seq[Command] = Seq(ignore, help, about, tasks, settingsCommand, loadProject,
 		projects, project, reboot, read, history, set, sessionCommand, inspect, loadProjectImpl, loadFailed, Cross.crossBuild, Cross.switchVersion,
 		setOnFailure, clearOnFailure, stashOnFailure, popOnFailure,
-		ifLast, multi, shell, continuous, eval, alias, append, last, lastGrep, export, boot, nop, call, exit, act)
+		ifLast, multi, shell, continuous, eval, alias, append, last, lastGrep, export, boot, nop, call, exit, act) ++
+		compatCommands
 	def DefaultBootCommands: Seq[String] = LoadProject :: (IfLast + " " + Shell) :: Nil
 
 	def boot = Command.make(BootCommand)(bootParser)