SUMMARY FindOpenEXR looks for 'libIlmImf' while this is renamed to 'libOpenEXR' in OpenEXR 3+. STEPS TO REPRODUCE 1. sudo apt install extra-cmake-modules 2. sudo apt install libopenexr-dev libilmbase-dev 2. Use the 'FindOpenEXR' cmake module in a CMakeLists.txt project OBSERVED RESULT CMake error message: Could NOT find OpenEXR (missing: OpenEXR_ILMIMF_LIBRARY) EXPECTED RESULT OpenEXR_FOUND: True SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: Kubuntu 22.10 + backports KDE Plasma Version: 5.26.2 KDE Frameworks Version: 5.99.0 Qt Version: 5.15.6 ADDITIONAL INFORMATION