diff -Naur source-old/src/CMakeLists.txt source-new/src/CMakeLists.txt
--- source-old/src/CMakeLists.txt	1969-12-31 21:00:01.000000000 -0300
+++ source-new/src/CMakeLists.txt	2021-10-29 12:03:06.461399341 -0300
@@ -362,10 +360,8 @@
 	if (EXISTS ${EXTERNAL_SRC_DIR}/git/openal AND STATIC_OPENAL)
 		amsg("${CL_YEL}Building OpenAL static from external/git mirror${CL_RST}")
 		ExternalProject_Add(OpenAL
-			SOURCE_DIR ${CMAKE_CURRENT_BINARY_DIR}/openal
+			SOURCE_DIR "${EXTERNAL_SRC_DIR}/git/openal"
 			BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/openal_static
-			UPDATE_COMMAND ""
-			GIT_REPOSITORY "${EXTERNAL_SRC_DIR}/git/openal"
 			${EXTERNAL_DEFS}
 			${CMAKE_EXTERNAL_DEFS}
 			-DALSOFT_BACKEND_DSOUND=OFF