having trouble building espruino for STM32F411DISCOVERY

The output of:

arm-none-eabi-gcc --version

is:

arm-none-eabi-gcc (4.8.2-14ubuntu1+6) 4.8.2
Copyright (C) 2013 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

so it's not 5.4 like you said earlier. I'll work on the tar-extraction method now.