I had tried many times, but it still fails
Results:
ying@ying-MS-7B22:~/esp/micropython-esp32/ports/esp32$ make
Use make V=1 or set BUILD_VERBOSE in your environment to increase build verbosity.
16:45:18.132237 git.c:344 trace: built-in: git show -s '--pretty=format:%H'
** WARNING **
The git hash of ESP IDF does not match the supported version
The build may complete and the firmware may work but it is not guaranteed
ESP IDF path: /home/ying/esp/esp-idf
Current git hash: a0644bf
Supported git hash: 2c95a77
16:45:18.148349 git.c:344 trace: built-in: git describe
CC /home/ying/esp/esp-idf/components/bootloader_support/src/bootloader_flash.c
/home/ying/esp/esp-idf/components/bootloader_support/src/bootloader_flash.c:16:10: fatal error: bootloader_flash.h: No such file or directory
#include <bootloader_flash.h>
^~~~~~~~~~~~~~~~~~~~
compilation terminated.
Makefile:897: recipe for target 'build/bootloader//home/ying/esp/esp-idf/components/bootloader_support/src/bootloader_flash.o' failed
make: *** [build/bootloader//home/ying/esp/esp-idf/components/bootloader_support/src/bootloader_flash.o] Error 1

I followed the README file, but it still doesn't work.
（See issue: micropython/micropython-esp32#1 ）