RPATH for Dummies
2 minute read.
This is the blog post I wish I had 5 hours ago, here to hopefully save someone else some time.
rpath
MacOS allows embedding paths to dependencies to shared libraries in executables and shared libraries.
List paths with:
otool -L <path-to-the-binary>
Modify the rpath with:
install_name_tool -change <old-path> <new-path> <path-to-the-binary>
-change will keep possible other metadata for version range, which would otherwise be
removed with install_name_tool -delete_rpath <old-path> -add_rpath <new-path> <path-to-the-binary>.
Additionally the executable can contain a list of “run paths”/rpaths, that are searched
if the path to a shared library contains @rpath.
Special: @loader_path, @rpath, @executable_path
Summarizing this wonderful blog post: “@executable path, @load path and @rpath” 1
@loader_path specifies the path of the loading binary (executable or shared library).
@executable_path specifies the path of the loading executable.
@rpath tells the runtime linker to search the “rpath”, which is a list of search paths
embedded in the executable.
CMake RPATH
CMake has two sets of run paths: INSTALL_RPATH and BUILD_RPATH. For running binaries
from the build directory, BUILD_RPATH is used while the install target will modify the
executable and shared library rpaths to use INSTALL_RPATH.
You can override these with CMAKE_INSTALL_RPATH 2 and CMAKE_BUILD_RPATH 3.
See also “RPATH Handling” documentation of CMake 4.