Trouble compiling Tensorflow Lite for Espruino WiFi

Hi,

I'm trying to enable TensorFlow lite on the Espruino Wifi. My build machine is Ubuntu 18.04. I can build the default binaries with

make clean && PAD_FOR_BOOTLOADER=1  BOARD=ESPRUINOWIFI make

The binary file uploads OK over the Web IDE and works fine as far as I can tell.
However, when I try to include TensorFlow:

make clean && PAD_FOR_BOOTLOADER=1 USE_TENSORFLOW=1 BOARD=ESPRUINOWIFI RELEASE=1 make

I get reference errors to _kill and _getpid and the LD phase fails:

/home/coniot/Espruino_build/source/repos/github/espruino/Espruino/gcc-arm-none-eabi-8-2018-q4-major/bin/../lib/gcc/arm-none-eabi/8.2.1/../../../../arm-none-eabi/bin/ld: /home/coniot/Espruino_build/source/repos/github/espruino/Espruino/gcc-arm-none-eabi-8-2018-q4-major/bin/../lib/gcc/arm-none-eabi/8.2.1/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/softfp/libg_nano.a(lib_a-signalr.o): in function `_kill_r':
signalr.c:(.text._kill_r+0xe): undefined reference to `_kill'
/home/coniot/Espruino_build/source/repos/github/espruino/Espruino/gcc-arm-none-eabi-8-2018-q4-major/bin/../lib/gcc/arm-none-eabi/8.2.1/../../../../arm-none-eabi/bin/ld: /home/coniot/Espruino_build/source/repos/github/espruino/Espruino/gcc-arm-none-eabi-8-2018-q4-major/bin/../lib/gcc/arm-none-eabi/8.2.1/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/softfp/libg_nano.a(lib_a-signalr.o): in function `_getpid_r':
signalr.c:(.text._getpid_r+0x0): undefined reference to `_getpid'
collect2: error: ld returned 1 exit status
make/targets/ARM.make:2: recipe for target 'espruino_2v05.429_wifi.elf' failed
make: *** [espruino_2v05.429_wifi.elf] Error 1

Any ideas what goes wrong and how I could enable TensorFlow on Espruino WiFi?

• Jussi