cmake: add an option named WITH_FMT_VERSION

so we can optionally force cmake to use the fmt submodule even if
fmtlib is available in system.

Signed-off-by: Kefu Chai <tchaikov@gmail.com>

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 42972391210195b5d8e3b5ac8a935199010fd5df..f29d173b3cdf3ec8282fe0db1ad7d60083c34589 100644 (file)
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -321,7 +321,8 @@ if(NOT TARGET RapidJSON::RapidJSON)
 endif()
 
 option(WITH_FMT_HEADER_ONLY "use header-only version of fmt library" OFF)
-find_package(fmt 7.0.0 QUIET)
+option(WITH_FMT_VERSION "build with fmt version" 7.0.0)
+find_package(fmt ${WITH_FMT_VERSION} QUIET)
 if(fmt_FOUND)
   include_directories(SYSTEM "${fmt_INCLUDE_DIR}")
 else()