curl.cmake included twice build error

Author: ChristopherHX

ext/curl.cmake

@@ -1,5 +1,12 @@
 include(ExternalProject)
 
+if(TARGET curl)
+    set(CURL_FOUND TRUE)
+    set(CURL_LIBRARIES curl)
+    set(CURL_INCLUDE_DIRS ${CMAKE_BINARY_DIR}/ext/curl/include/)
+    return()
+endif()
+
 if (NOT CURL_EXT_EXTRA_OPTIONS)
     set(CURL_EXT_EXTRA_OPTIONS )
 endif()
@@ -30,6 +37,7 @@ endif()
 ExternalProject_Add(
         curl_ext
         ${CURL_EXT_PROPERTIES}
+        DOWNLOAD_EXTRACT_TIMESTAMP TRUE
         INSTALL_DIR ${CMAKE_BINARY_DIR}/ext/curl
         BUILD_BYPRODUCTS "${CMAKE_BINARY_DIR}/ext/curl/lib/libcurl.a"
         CMAKE_ARGS "-DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/ext/curl" "-DBUILD_CURL_EXE=OFF" "-DBUILD_SHARED_LIBS=OFF" "-DCURL_STATICLIB=ON" "-DCURL_DISABLE_LDAP=ON" "-DCURL_USE_LIBSSH2=OFF" "-DCURL_USE_OPENLDAP=OFF" "-DUSE_LIBIDN2=OFF" "-DCURL_USE_LIBPSL=OFF" "-DENABLE_WEBSOCKETS=ON" "-DCMAKE_INSTALL_LIBDIR=lib" "-DCMAKE_ASM_COMPILER=${CMAKE_ASM_COMPILER}" "-DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}" "-DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}" "-DCMAKE_C_FLAGS=${CMAKE_C_FLAGS}" "-DCMAKE_LINK_FLAGS=${CMAKE_LINK_FLAGS}" "-DCMAKE_LIBRARY_ARCHITECTURE=${CMAKE_LIBRARY_ARCHITECTURE}" ${CURL_EXT_EXTRA_OPTIONS}