It is hard to solve problems, if there is no sufficient information about the configuration/setup:

• What was the command string when running Build task?
• What did you try already? Did you try to compile a single file?
• Is Update workspace task correctly executed?
• ...
  It will be a lot easier if you describe your problem with as much detail as possible.

Anyway, a quick googling of this error code (Make *** Error 1) tells us, that this is actually GCC problem, not Make. Hence, check your GCC path and try to compile a single file by running Compile task on focused file. In my case, compile-time error is neatly displayed in terminal:

C:/Users/domen/AppData/Roaming/GNU MCU Eclipse/ARM Embedded GCC/7.3.1-1.1-20180724-0637/bin/arm-none-eabi-gcc -c -mcpu=cortex-m0 -mthumb   -DAVOID_EMPTY_DEFINE_FIELD_C -DUSE_HAL_DRIVER -DSTM32F051x8 -IInc -IDrivers/STM32F0xx_HAL_Driver/Inc -IDrivers/STM32F0xx_HAL_Driver/Inc/Legacy -IDrivers/CMSIS/Device/ST/STM32F0xx/Include -IDrivers/CMSIS/Include -Og -Wall -fdata-sections -ffunction-sections -g -gdwarf-2 -MMD -MP -MF"build/main.d" -Wa,-a,-ad,-alms=build/main.lst Src/main.c -o build/main.o
Src/main.c: In function 'main':
Src/main.c:137:3: error: expected ';' before '}' token
   }
   ^
make: *** [Makefile:156: build/main.o] Error 1
The terminal process terminated with exit code: 1

This is crazy, but all problems is out when I was change GCC version:
from 8.2.1-1.3-20190202-1016 to 7.3.1-1.1-20180724-0637

May be need to add this information to Readme?

Will investigate and add notes if necessary.
Thank you.

Thanks, added a note to a README.