参考 https://github.com/RT-Thread-packages/lwext4/blob/master/README.md
参考：https://www.apache.org/licenses/GPL-compatibility.html
Apache 2 software can therefore be included in GPLv3 projects, because the GPLv3 license accepts our software into GPLv3 works. However, GPLv3 software cannot be included in Apache projects. The licenses are incompatible in one direction only, and it is a result of ASF's licensing philosophy and the GPLv3 authors' interpretation of copyright law.
所以我认为 Apache license 的 RT-Thread 包含了 GPL 的代码也是不恰当的，会有潜在的法律问题。
虽然 package 部分不是和 RT-thread 一起发布，但是下载安装后会参与编译链接，这个会导致 GPL 传染。See https://opensource.stackexchange.com/questions/13697/using-gpl-library-in-my-own-apache-library。
参考 https://github.com/RT-Thread-packages/lwext4/blob/master/README.md
参考：https://www.apache.org/licenses/GPL-compatibility.html
所以我认为 Apache license 的 RT-Thread 包含了 GPL 的代码也是不恰当的，会有潜在的法律问题。
虽然 package 部分不是和 RT-thread 一起发布，但是下载安装后会参与编译链接，这个会导致 GPL 传染。See https://opensource.stackexchange.com/questions/13697/using-gpl-library-in-my-own-apache-library。