When WebKit is built the path of the repository (where you have the checkout) is stored in the binaries in different ways:

 - The path to the WebKit libraries is stored as an rpath on the ELF binaries
 - The CMake system also defines some constant strings to the build like WEBKIT_EXEC_PATH and WEBKIT_INJECTED_BUNDLE_PATH that end going into the binaries as default values.
   This default values can be overriden at run-time via environment variables, but the current tooling is not doing that.

This means that if you build WebKit in a directory and then move the directory to a different path (without rebuilding) you are going to find errors and crashes:

Example of error:
                 Release/bin/MiniBrowser: error while loading shared libraries: libwebkit2gtk-4.0.so.37: cannot open shared object file: No such file or directory


This is not an issue with the flatpak build, because the flatpak build maps the buildirectory to /app so the path doesn't change in that case even if you move the directory.

But it is an issue for builds not using flatpak. Specifically I found this on a bots that I'm working on where the builder builds on a different path than the tester (and the tester downloads the build product from the builder, doesn't build it)