show how to restrict the default build to your user defined environments

lib/exampletask/platformio.ini

@@ -1,3 +1,8 @@
+[platformio]
+#if you want a pio run to only build
+#your special environments you can set this here
+#by uncommenting the next line
+#default_envs = testboard
 [env:testboard]
 board = m5stack-atom
 lib_deps = 

platformio.ini

@@ -8,14 +8,14 @@
 ; Please visit documentation for the other options and examples
 ; https://docs.platformio.org/page/projectconf.html
 [platformio]
-extra_configs=
-	lib/*task*/platformio.ini
 default_envs=
 	m5stack-atom
 	m5stack-atom-canunit
 	m5stickc-atom-canunit
 	nodemcu-homberger
-	
+extra_configs=
+	lib/*task*/platformio.ini
+
 [env]
 platform = espressif32
 framework = arduino