`opt` is hard-coded in `humble`

@clalancette I installed ROS 2 in a directory different from /opt/ros/humble. The yaml_cpp_vendor package installs to the root/opt/yaml_cpp_vendor/, where root is my installation path.

$ find output/export/root/ -name *yaml[-_]cpp* | cut -d '/' -f 3-
root/share/colcon-core/packages/yaml_cpp_vendor
root/share/ament_index/resource_index/parent_prefix_path/yaml_cpp_vendor
root/share/ament_index/resource_index/package_run_dependencies/yaml_cpp_vendor
root/share/ament_index/resource_index/packages/yaml_cpp_vendor
root/share/yaml_cpp_vendor
root/share/yaml_cpp_vendor/cmake/yaml_cpp_vendorConfig.cmake
root/share/yaml_cpp_vendor/cmake/yaml_cpp_vendor-extras.cmake
root/share/yaml_cpp_vendor/cmake/yaml_cpp_vendorConfig-version.cmake
root/share/yaml_cpp_vendor/environment/yaml_cpp_vendor_library_path.dsv
root/share/yaml_cpp_vendor/environment/yaml_cpp_vendor_library_path.sh
root/opt/yaml_cpp_vendor
root/opt/yaml_cpp_vendor/share/cmake/yaml-cpp
root/opt/yaml_cpp_vendor/share/cmake/yaml-cpp/yaml-cpp-config.cmake
root/opt/yaml_cpp_vendor/share/cmake/yaml-cpp/yaml-cpp-config-version.cmake
root/opt/yaml_cpp_vendor/share/cmake/yaml-cpp/yaml-cpp-targets.cmake
root/opt/yaml_cpp_vendor/share/cmake/yaml-cpp/yaml-cpp-targets-release.cmake
root/opt/yaml_cpp_vendor/share/pkgconfig/yaml-cpp.pc
root/opt/yaml_cpp_vendor/lib/libyaml-cpp.so.0.7
root/opt/yaml_cpp_vendor/lib/libyaml-cpp.so
root/opt/yaml_cpp_vendor/lib/libyaml-cpp.so.0.7.0
root/opt/yaml_cpp_vendor/include/yaml-cpp

As a result, yaml-cpp is not found by ur_calibration. This fix helps

diff --git a/CMakeLists.txt b/CMakeLists.txt
index badc1b4..2d4ea7a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -59,7 +59,7 @@ macro(build_yaml_cpp)
     DIRECTORY
       ${CMAKE_CURRENT_BINARY_DIR}/yaml_cpp_install/
     DESTINATION
-      ${CMAKE_INSTALL_PREFIX}/opt/yaml_cpp_vendor
+      ${CMAKE_INSTALL_PREFIX}
     USE_SOURCE_PERMISSIONS
   )
 endmacro()
@@ -70,21 +70,6 @@ endmacro()
 find_package(yaml-cpp QUIET NO_CMAKE_PACKAGE_REGISTRY)
 if(FORCE_BUILD_VENDOR_PKG OR NOT yaml-cpp_FOUND)
   build_yaml_cpp()
-
-  if(WIN32)
-    ament_environment_hooks(env_hook/yaml_cpp_vendor_library_path.bat)
-    set(ENV_VAR_NAME "PATH")
-    set(ENV_VAR_VALUE "opt\\yaml_cpp_vendor\\bin")
-  else()
-    ament_environment_hooks(env_hook/yaml_cpp_vendor_library_path.sh)
-    if(APPLE)
-      set(ENV_VAR_NAME "DYLD_LIBRARY_PATH")
-    else()
-      set(ENV_VAR_NAME "LD_LIBRARY_PATH")
-    endif()
-    set(ENV_VAR_VALUE "opt/yaml_cpp_vendor/lib")
-  endif()
-  ament_environment_hooks(env_hook/yaml_cpp_vendor_library_path.dsv.in)
 else()
   message(STATUS "Found yaml-cpp ${yaml-cpp_VERSION} in path ${yaml-cpp_CONFIG}")
 endif()
diff --git a/yaml_cpp_vendor-extras.cmake.in b/yaml_cpp_vendor-extras.cmake.in
index deac98c..0706bc6 100644
--- a/yaml_cpp_vendor-extras.cmake.in
+++ b/yaml_cpp_vendor-extras.cmake.in
@@ -3,9 +3,9 @@ find_package(yaml-cpp QUIET)
 if(NOT yaml-cpp_FOUND)
   # add the local Modules directory to the modules path
   if(WIN32)
-    set(yaml-cpp_DIR "${@PROJECT_NAME@_DIR}/../../../opt/yaml_cpp_vendor/CMake")
+    set(yaml-cpp_DIR "${@PROJECT_NAME@_DIR}/../../../CMake")
   else()
-    set(yaml-cpp_DIR "${@PROJECT_NAME@_DIR}/../../../opt/yaml_cpp_vendor/share/cmake/yaml-cpp")
+    set(yaml-cpp_DIR "${@PROJECT_NAME@_DIR}/../../../lib/cmake/yaml-cpp")
   endif()
   message(STATUS "Setting yaml-cpp_DIR to: '${yaml-cpp_DIR}'")

It looks like this afterward:

$ find output/export/root/ -name *yaml[-_]cpp* | cut -d '/' -f 3-
root/share/cmake/yaml-cpp
root/share/cmake/yaml-cpp/yaml-cpp-config.cmake
root/share/cmake/yaml-cpp/yaml-cpp-config-version.cmake
root/share/cmake/yaml-cpp/yaml-cpp-targets.cmake
root/share/cmake/yaml-cpp/yaml-cpp-targets-release.cmake
root/share/pkgconfig/yaml-cpp.pc
root/share/colcon-core/packages/yaml_cpp_vendor
root/share/ament_index/resource_index/parent_prefix_path/yaml_cpp_vendor
root/share/ament_index/resource_index/package_run_dependencies/yaml_cpp_vendor
root/share/ament_index/resource_index/packages/yaml_cpp_vendor
root/share/yaml_cpp_vendor
root/share/yaml_cpp_vendor/cmake/yaml_cpp_vendorConfig.cmake
root/share/yaml_cpp_vendor/cmake/yaml_cpp_vendor-extras.cmake
root/share/yaml_cpp_vendor/cmake/yaml_cpp_vendorConfig-version.cmake
root/lib/libyaml-cpp.so.0.7
root/lib/libyaml-cpp.so
root/lib/libyaml-cpp.so.0.7.0
root/include/yaml-cpp