Ensure library directory existence prior to using it

Author: ianfixes

CHANGELOG.md

@@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 - Example sketches with no configured platforms were printing the wrong configuration values to the debug message
+- Libraries directory was not being automatically created prior to attempting to change directory into it
 
 ### Security
 

exe/arduino_ci.rb

@@ -530,6 +530,11 @@ def perform_example_compilation_tests(cpp_library, config)
 config = ArduinoCI::CIConfig.default.from_project_library
 @backend = ArduinoCI::ArduinoInstallation.autolocate!
 inform("Located arduino-cli binary") { @backend.binary_path.to_s }
+if @backend.lib_dir.exist?
+  inform("Found libraries directory") { @backend.lib_dir }
+else
+  assure("Creating libraries directory") { @backend.lib_dir.mkpath || true }
+end
 
 # run any library init scripts from the library itself.
 perform_custom_initialization(config)