CppCon 2024

Most C++ developers are familiar with the type of errors that arise when a shared library is not found. If they are really unlucky, they are have also faced a situation where the the wrong version of a library is loaded. However, a lot of us resort to suboptimal solutions just to get going, without fully addressing the root causes.

A lot of the time, we focus on the “build” process, that is, producing our binaries and executables. But getting the runtime linker/loader to locate the right libraries (and the right versions!) has a unique set of challenges that  should not be overlooked - after all, running the executables is critical for running tests, continuous integration, and obviously end-users running our apps and services.

Managing dependencies continues to be one of the top frustrations of C++ developers as per the most recents ISO C++ Developer Surveys. When it comes to shared libraries - different applications try to locate them at different times: the build system (e.g. CMake or Autotools) when configuring the build, the linker at build time, and the dynamic linker/loader at runtime.

This talk will cover in detail the different scenarios in which shared libraries need to be located, and how this is handled by package managers, build systems, and the the OS level. Emphasis will be placed on familiarizing the developer with the relevant tooling across multiple platforms, as well as associated concepts (e.g. RPATHs).

An often overlooked aspect will also be covered: how to create a self-contained, relocatable bundle for our user-facing applications, decoupled from the developer environment, as opposed to “works on my machine”.