From 893f120dee477dc3f5f1af140034a0c1edf77503 Mon Sep 17 00:00:00 2001
From: Ethan Atkins <contact@ethanatkins.com>
Date: Sat, 27 Jul 2019 12:47:00 -0700
Subject: [PATCH] Don't rewrite RunFromSource.classpath every time

In the sbt project, we often spuriously re-doc a number of projects that
haven't changed because we modify a file in the resource path.
---
 build.sbt | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/build.sbt b/build.sbt
index 1f61a3539..699acd08f 100644
--- a/build.sbt
+++ b/build.sbt
@@ -5,6 +5,7 @@ import com.typesafe.tools.mima.core._, ProblemFilters._
 import local.Scripted
 import scala.xml.{ Node => XmlNode, NodeSeq => XmlNodeSeq, _ }
 import scala.xml.transform.{ RewriteRule, RuleTransformer }
+import scala.util.Try
 
 ThisBuild / version := {
   val v = "1.3.0-SNAPSHOT"
@@ -402,7 +403,9 @@ lazy val scriptedSbtReduxProj = (project in file("scripted-sbt-redux"))
       val extDepsCp = (externalDependencyClasspath in Compile in LocalProject("sbtProj")).value
       val cpStrings = (mainClassDir +: testClassDir +: classDirs) ++ extDepsCp.files map (_.toString)
       val file = (resourceManaged in Compile).value / "RunFromSource.classpath"
-      IO.writeLines(file, cpStrings)
+      if (!file.exists || Try(IO.readLines(file)).getOrElse(Nil).toSet != cpStrings.toSet) {
+        IO.writeLines(file, cpStrings)
+      }
       List(file)
     },
     mimaSettings,