Use https://www.mobileread.com/forums/showthread.php?p=3921722 if you have an issue and can't narrow down proper cause/repro as other users on there may help you. Github is strictly for the technical side, not support.
по русски: http://4pda.ru/forum/index.php?s=&showtopic=886480&view=findpost&p=92768601
This tree uses both Pocketbook SDK for dynamic linking, as well as static musl libc cross compiler for critical services (ssh and smb). The SDK has poor portability between firmware versions, but allows for using ncurses or openssl (those are not suitable for static linking).
For static musl cross compiler: https://toolchains.bootlin.com/downloads/releases/toolchains/armv7-eabihf/tarballs/armv7-eabihf--musl--stable-2018.11-1.tar.bz2 For SDK cross compiler: https://github.com/ezdiy/pocketbook-sdk5/archive/master.tar.gz
Unpack, and point your $PATH to 'bin' folder in both SDKs (gcc are differentiated by cross prefix, cc and cc5 in makefile).
Alternatively you can use a Docker image for compiling and linking, it contains the necessary (i386) packages and the above compilers/toolchains.
Requirements: installed Docker environment
To prepare the Docker image, clone this repository with its submodule(s), if you haven't yet:
git clone https://github.com/ezdiy/pbjb.git --recurse-submodules --shallow-submodules
build the image:
cd pbjb
docker build -t pbjb .
To build pbjb, run the image (from within the same pbjb directory), this runs 'make':
./rundocker.sh
You can also specify a command to run, e.g. to run a 'make clean':
./rundocker.sh make clean