Fixed upstream in 3a3e69417109abd92f0640ec2c63d1c4dbb7274d

--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,1 +1,1 @@
-CPMAddPackage(NAME md4c
+CPMFindPackage(NAME md4c
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -524,7 +524,7 @@ IF(ENABLE_SPOUT AND SPOUT_LIBRARY_DLL)
      CONFIGURE_FILE(${SPOUT_LIBRARY_DLL} ${CMAKE_CURRENT_BINARY_DIR} COPYONLY)
 ENDIF()
 
-SET(STELMAIN_DEPS md4c-html ${ZLIB_LIBRARIES} glues_stel ${STELLARIUM_STATIC_PLUGINS_LIBRARIES} ${STELLARIUM_QT_LIBRARIES} ${SPOUT_LIBRARY} ${STD_EXECUTION_LIBS})
+SET(STELMAIN_DEPS md4c::md4c-html ${ZLIB_LIBRARIES} glues_stel ${STELLARIUM_STATIC_PLUGINS_LIBRARIES} ${STELLARIUM_QT_LIBRARIES} ${SPOUT_LIBRARY} ${STD_EXECUTION_LIBS})
 IF(USE_BUNDLED_QTCOMPRESS)
      SET(STELMAIN_DEPS ${STELMAIN_DEPS} qtcompress_stel)
 ENDIF()