cargo make issue: invalid type: map, expected a string for key package.edition

[KenLee12323]

I am trying to build from source and put it in the redis docker image. I am using ubuntu 16.04. I typed the following commands:
$ git clone --recursive https://github.com/RedisJSON/RedisJSON.git
$ cd RedisJSON
$ sudo apt-get install rust
$ make

And it gives the following error msg:
error: failed to parse manifest at xxx/RedisJSON/json_path/Cargo.toml
Caused by:
invalid type: map, expected a string for key package.edition

Someone previously mentioned that it is solved by:

          closed via solved by reset rust env

Originally posted by @arthurkiller in #1071 (comment)

But I am too stupid to understand. Why is building from source that hard. I know there is redis-stack available, but it doesn't contain redisAI, which is not an option for me. Indeed, I have also tried to build the other modules, all gives me different kinds of errors. Is there any other method that can save me time?

Many thanks for the help!