Linking everything together...
" -lc -Wl,--end-group -lm -lgcc -lstdc++
c:/users/richa/appdata/local/arduino15/packages/stm32/tools/xpack-arm-none-eabi-gcc/9.2.1-1.1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Users\Richa\AppData\Local\Temp\arduino_build_788410\libraries\SrcWrapper\HAL\stm32yyxx_hal_cortex.c.o: in function `HAL_NVIC_SetPriorityGrouping':

stm32yyxx_hal_cortex.c:(.text.HAL_NVIC_SetPriorityGrouping+0xe): undefined reference to `assert_failed'

c:/users/richa/appdata/local/arduino15/packages/stm32/tools/xpack-arm-none-eabi-gcc/9.2.1-1.1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Users\Richa\AppData\Local\Temp\arduino_build_788410\libraries\SrcWrapper\HAL\stm32yyxx_hal_cortex.c.o: in function `HAL_NVIC_SetPriority':

stm32yyxx_hal_cortex.c:(.text.HAL_NVIC_SetPriority+0x10): undefined reference to `assert_failed'

c:/users/richa/appdata/local/arduino15/packages/stm32/tools/xpack-arm-none-eabi-gcc/9.2.1-1.1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: stm32yyxx_hal_cortex.c:(.text.HAL_NVIC_SetPriority+0x1c): undefined reference to `assert_failed'

c:/users/richa/appdata/local/arduino15/packages/stm32/tools/xpack-arm-none-eabi-gcc/9.2.1-1.1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Users\Richa\AppData\Local\Temp\arduino_build_788410\libraries\SrcWrapper\HAL\stm32yyxx_hal_cortex.c.o: in function `HAL_NVIC_ClearPendingIRQ':

stm32yyxx_hal_cortex.c:(.text.HAL_NVIC_ClearPendingIRQ+0xa): undefined reference to `assert_failed'

c:/users/richa/appdata/local/arduino15/packages/stm32/tools/xpack-arm-none-eabi-gcc/9.2.1-1.1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Users\Richa\AppData\Local\Temp\arduino_build_788410\libraries\SrcWrapper\HAL\stm32yyxx_hal_pwr_ex.c.o: in function `HAL_PWREx_ControlVoltageScaling':

stm32yyxx_hal_pwr_ex.c:(.text.HAL_PWREx_ControlVoltageScaling+0x14): undefined reference to `assert_failed'

Multiple libraries were found for "SrcWrapper.h"
c:/users/richa/appdata/local/arduino15/packages/stm32/tools/xpack-arm-none-eabi-gcc/9.2.1-1.1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Users\Richa\AppData\Local\Temp\arduino_build_788410\libraries\SrcWrapper\HAL\stm32yyxx_hal_rcc.c.o:stm32yyxx_hal_rcc.c:(.text.HAL_RCC_OscConfig+0x1a): more undefined references to `assert_failed' follow

 Used: C:\Users\Richa\AppData\Local\Arduino15\packages\STM32\hardware\stm32\1.8.0\libraries\SrcWrapper
collect2.exe: error: ld returned 1 exit status
Using library SrcWrapper at version 1.0.1 in folder: C:\Users\Richa\AppData\Local\Arduino15\packages\STM32\hardware\stm32\1.8.0\libraries\SrcWrapper
exit status 1
Error compiling for board Nucleo-64.