These were the errors I was receiving:

CC: chip/stm32_allocateheap.c chip/stm32_allocateheap.c:122:6: warning: #warning "CONFIG_HEAP2_BASE or CONFIG_HEAP2_SIZE are zero. No HEAP2 enabled!" [-Wcpp]
122 | # warning "CONFIG_HEAP2_BASE or CONFIG_HEAP2_SIZE are zero. No HEAP2 enabled!"
| ^~~
CC: stm32_userspace.c stm32_userspace.c:47:4: error: #error "CONFIG_NUTTX_USERSPACE must be 0x08040000 to match memory.ld"
47 | # error "CONFIG_NUTTX_USERSPACE must be 0x08040000 to match memory.ld"
| ^~~~~
make[1]: *** [Makefile:54: stm32_userspace.o] Error 1
make: *** [tools/Unix.mk:526: nuttx] Error 2

The HEAP2_BASE was fixed this defining:

CONFIG_HEAP2_BASE=0xc0000000
CONFIG_HEAP2_SIZE=33554432

About the CONFIG_NUTTX_USERSPACE I defined it to 0x08040000 as suggested, although in the previous NuttX kernel used on Meadow it was defined to 0x08040200.

CONFIG_NUTTX_USERSPACE=0x08040000