From 5bf2eab6a421f261e3c543468209929b5ca8135b Mon Sep 17 00:00:00 2001
From: Christian Parpart <christian@parpart.family>
Date: Wed, 27 Nov 2019 12:11:57 +0100
Subject: [PATCH] Fixes CMake caching issues on Windows.

---
 cmake/EthCheckCXXCompilerFlag.cmake | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/cmake/EthCheckCXXCompilerFlag.cmake b/cmake/EthCheckCXXCompilerFlag.cmake
index c6ed35b4e..3e62885fe 100644
--- a/cmake/EthCheckCXXCompilerFlag.cmake
+++ b/cmake/EthCheckCXXCompilerFlag.cmake
@@ -10,7 +10,9 @@ include(CheckCXXCompilerFlag)
 #
 function(eth_add_cxx_compiler_flag_if_supported FLAG)
   # Remove leading - or / from the flag name.
-  string(REGEX REPLACE "^-|/" "" name ${FLAG})
+  string(REGEX REPLACE "^[-/]" "" name ${FLAG})
+  # Deletes any ':' because it's invalid variable names.
+  string(REGEX REPLACE ":" "" name ${name})
   check_cxx_compiler_flag(${FLAG} ${name})
   if(${name})
     add_compile_options(${FLAG})