Recreate the archive if ANY of the core files (including platform.txt) has changed

Author: facchinm

src/arduino.cc/builder/phases/core_builder.go

@@ -84,8 +84,11 @@ func compileCore(buildPath string, buildProperties properties.Map, verbose bool,
 		}
 	}
 
+	// Recreate the archive if ANY of the core files (including platform.txt) has changed
+	realCoreFolder := utils.GetParentFolder(coreFolder, 2)
+
 	targetArchivedCore := builder_utils.GetCoreArchivePath(buildProperties[constants.BUILD_PROPERTIES_FQBN])
-	noNeedToRecompile := builder_utils.CheckIfRecompileIsAvoidable(coreFolder, targetArchivedCore)
+	noNeedToRecompile := builder_utils.CheckIfRecompileIsAvoidable(realCoreFolder, targetArchivedCore)
 
 	if noNeedToRecompile {
 		// use archived core

src/arduino.cc/builder/utils/utils.go

@@ -365,6 +365,16 @@ func FindFilesInFolder(files *[]string, folder string, extensions CheckExtension
 	return gohasissues.Walk(folder, walkFunc)
 }
 
+func GetParentFolder(basefolder string, n int) string {
+	tempFolder := basefolder
+	i := 0
+	for i < n {
+		tempFolder = filepath.Dir(tempFolder)
+		i++
+	}
+	return tempFolder
+}
+
 func AppendIfNotPresent(target []string, elements ...string) []string {
 	for _, element := range elements {
 		if !SliceContains(target, element) {