dynamic library install problem on macOS

[jclark]

When I build and install on macOS, the installed binaries don't work:

% str2str
dyld[76494]: Library not loaded: @rpath/librtklib.dylib
  Referenced from: <9A40F8A3-2829-3625-A427-288739C63802> /usr/local/bin/str2str
  Reason: no LC_RPATH's found
zsh: abort      str2str

My coding agent tells me the right fix is:

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2aa958ff..5133d4f4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,6 +16,15 @@ include(CTest)

 option(IERS_MODEL "Use Earth models from IERS" OFF)

+# make installed executables locate the rtklib shared library relative to
+# themselves (<prefix>/bin -> <prefix>/lib) so the install tree is relocatable
+set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
+if(APPLE)
+    set(CMAKE_INSTALL_RPATH "@loader_path/../lib")
+elseif(UNIX)
+    set(CMAKE_INSTALL_RPATH "$ORIGIN/../lib")
+endif()
+
 set(TEST_DATA_DIR ${CMAKE_CURRENT_SOURCE_DIR}/test/data)

 # configure rtklib

This does indeed solve the problem, and seems plausible, but I know nothing of CMake