Merge pull request #4162 from holdenk/support-double-dash-for-logging-levels

Support -- for log levels

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

@@ -67,7 +67,7 @@ $HelpCommand <regular expression>
 	This will be used as the default level for logging from commands, settings, and tasks.
 	Any explicit `logLevel` configuration in a project overrides this setting.
 
--$level
+-$level OR --$level
 
 	Sets the global logging level as described above, but does so before any other commands are executed on startup, including project loading.
 	This is useful as a startup option:
@@ -77,7 +77,9 @@ $HelpCommand <regular expression>
 
   def runEarly(command: String) = s"$EarlyCommand($command)"
   private[sbt] def isEarlyCommand(s: String): Boolean = {
-    val levelOptions = Level.values.toSeq map { "-" + _ }
+    val levelOptions = Level.values.toSeq flatMap { elem =>
+      List("-" + elem, "--" + elem)
+    }
     (s.startsWith(EarlyCommand + "(") && s.endsWith(")")) ||
     (levelOptions contains s)
   }

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

@@ -69,7 +69,8 @@ object BasicCommands {
   private[this] def earlyParser: State => Parser[String] = (s: State) => {
     val p1 = token(EarlyCommand + "(") flatMap (_ => otherCommandParser(s) <~ token(")"))
     val p2 = token("-") flatMap (_ => levelParser)
-    p1 | p2
+    val p3 = token("--") flatMap (_ => levelParser)
+    p1 | p2 | p3
   }
 
   private[this] def earlyHelp = Help(EarlyCommand, EarlyCommandBrief, EarlyCommandDetailed)

sbt/src/sbt-test/actions/early-command/test

@@ -1,2 +1,3 @@
 > -error
 > early(error)
+> --error