System Workbench for STM32

I updated eclipse to Luna Service Release 2 (4.4.2) and Cube to 4.12.0, now previous working projects no longer work.
I have the following two errors

/usr/bin/sh: gcc: command not found

make: *** Drivers/STM32F4xx_HAL_Driver/stm32f4xx_hal.o Error 127

Even if I create a simple new project with cube I still get the same errors.

Help would be gratefully appreciated.