Hey there! Let me break down what this niche CMake flag does for you—since I know tracking down details on some of OpenCV's more specific build options can feel like looking for a needle in a haystack.

• Core Goal
  This option is all about avoiding conflicts when installing OpenCV alongside other versions or system-wide library installations. It modifies the default install path structure to add unique, version-specific subdirectories, so your custom-built OpenCV doesn't overwrite or clash with existing OpenCV files on your system.

• Path Modifications in Action
  When you set INSTALL_TO_MANGLED_PATHS=ON, OpenCV tacks on extra hierarchy layers to its install paths. For example:

  • Instead of header files going to /usr/include/opencv4, they’ll end up in something like /usr/include/opencv4/opencv-4.8.0 (matching your OpenCV version).
  • Library files that normally live in /usr/lib/x86_64-linux-gnu will be moved to a versioned subdirectory under that path.

• When You’d Want to Use It

  • If you need multiple OpenCV versions on the same system (e.g., one for legacy projects, one for cutting-edge features), this flag keeps their files completely separated.
  • If you’re developing OpenCV plugins or custom builds and don’t want to mess with the system’s global OpenCV installation, this is a safe way to contain your build.
  • Pro tip: For regular, single-version use, leave this set to the default OFF—it keeps paths clean and makes referencing OpenCV in your projects simpler.

• How to Enable It
  You can set this during the CMake configuration step either via command line:

  cmake -DINSTALL_TO_MANGLED_PATHS=ON <path-to-opencv-source>
  

  Or if you’re using the CMake GUI, just find the INSTALL_TO_MANGLED_PATHS checkbox, tick it, and reconfigure your build.

内容的提问来源于stack exchange，提问作者alexS