Cant get beyond compiling

I can not seem to get beyond compiling and particularly at the statement: "Detecting libraries used..." (see the dump below). I have previously run Arduino on my machine but have since updated both OS and Java.

What am I doing wrong.

Arduino 1.8.7 Apple 10.14.1 Mojave

The dump:

/Applications/ -dump-prefs -logger=machine -hardware /Applications/ -hardware /Users/conorpower/Library/Arduino15/packages -tools /Applications/ -tools /Applications/ -tools /Users/conorpower/Library/Arduino15/packages -built-in-libraries /Applications/ -libraries /Users/conorpower/Documents/Arduino/libraries -fqbn=arduino:avr:uno -ide-version=10807 -build-path /var/folders/sj/5xbm18s95jx6xry14qj2ftfh0000gn/T/arduino_build_855956 -warnings=none -build-cache /var/folders/sj/5xbm18s95jx6xry14qj2ftfh0000gn/T/arduino_cache_293779 -prefs=build.warn_data_percentage=75 -verbose /var/folders/sj/5xbm18s95jx6xry14qj2ftfh0000gn/T/arduino_modified_sketch_907344/BareMinimum.ino
/Applications/ -compile -logger=machine -hardware /Applications/ -hardware /Users/conorpower/Library/Arduino15/packages -tools /Applications/ -tools /Applications/ -tools /Users/conorpower/Library/Arduino15/packages -built-in-libraries /Applications/ -libraries /Users/conorpower/Documents/Arduino/libraries -fqbn=arduino:avr:uno -ide-version=10807 -build-path /var/folders/sj/5xbm18s95jx6xry14qj2ftfh0000gn/T/arduino_build_855956 -warnings=none -build-cache /var/folders/sj/5xbm18s95jx6xry14qj2ftfh0000gn/T/arduino_cache_293779 -prefs=build.warn_data_percentage=75 -verbose /var/folders/sj/5xbm18s95jx6xry14qj2ftfh0000gn/T/arduino_modified_sketch_907344/BareMinimum.ino
Using board 'uno' from platform in folder: /Applications/
Using core 'arduino' from platform in folder: /Applications/

Detecting libraries used...
/Applications/ -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10807 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR -I/Applications/ -I/Applications/ /var/folders/sj/5xbm18s95jx6xry14qj2ftfh0000gn/T/arduino_build_855956/sketch/BareMinimum.ino.cpp -o /dev/null

Thank you.

The following solved my issue; its not obvious:

Apple no longer include the Command Line Tools package in upgrades to the OS. These are required to run Arduino and incidentally some Python editors.

Do the following:

  1. Go to Sign In - Apple

  2. Sign in. Don't worry, just sign in with your Apple ID. You don't have to be a developer.

  3. In the list that follows search for the Command_Line_Tools package that corresponds to your Mac upgrade. In my case it was for 10.14.

  4. Download and install that package. It may take a while to open this before it begins to install the package.

  5. After that Arduino should run normally.

Good luck,