--- CMakeLists.txt.orig	2020-05-13 05:15:56 UTC
+++ CMakeLists.txt
@@ -88,11 +88,13 @@ endif()
 # ==============================================================================
 # Check that submodule have been initialized and updated
 # ==============================================================================
+if (FALSE)
 if (NOT EXISTS ${PROJECT_SOURCE_DIR}/dependencies/cereal/include)
   message(FATAL_ERROR
     "\n submodule(s) are missing, please update your repository:\n"
     "  > git submodule update -i\n")
 endif()
+endif()
 
 # ==============================================================================
 # Additional cmake find modules
@@ -103,8 +105,8 @@ include(OptimizeForArchitecture)
 OptimizeForArchitecture()
 
 if (UNIX AND NOT OpenMVG_BUILD_COVERAGE)
-  set(CMAKE_C_FLAGS_RELEASE "-O3")
-  set(CMAKE_CXX_FLAGS_RELEASE "-O3")
+  #set(CMAKE_C_FLAGS_RELEASE "-O3")
+  #set(CMAKE_CXX_FLAGS_RELEASE "-O3")
 endif ()
 
 # ==============================================================================
@@ -260,7 +262,7 @@ endif()
 # - external by default if CERES_DIR_HINTS or find_package found a valid Ceres
 # - internal if ceres not found (ceres-solver+cxsparse+miniglog)
 # ==============================================================================
-find_package(Ceres QUIET HINTS ${CERES_DIR_HINTS})
+#find_package(Ceres QUIET HINTS ${CERES_DIR_HINTS}) # external ceres can't work because it requires fortran
 if (NOT Ceres_FOUND)
   set(OpenMVG_USE_INTERNAL_CERES ON)
   set(CERES_INCLUDE_DIRS