crosstools-ng can't find pthread.so

Question

I am trying to use crosstools-ng to compile a program that uses pthread, however for some reason the linker can\'t find the library. I have checked and the libraries are located

Answer 1

Using the GCC --sysroot=dir flag should fix the issue. This flag tells GCC to search both headers and libraries under the dir folder.

In your case, if you add --sysroot=/home/user/rpi_root to linker flags, ld will search for /home/user/rpi_root/lib/libpthread.so.0 instead of just /lib/libpthread.so.0.

This is particularly helpful to fix linking with fullpath to library.

When using CMake to generate build system, you should use SET(CMAKE_SYSROOT ${RPI_ROOT_PATH}), where RPI_ROOT_PATH contains the path to the RPi sysroot instead of directly set compiler flags.