diff --git a/include/external/clara.hpp b/include/external/clara.hpp
index 3f2d13bf..88a5e9fe 100644
--- a/include/external/clara.hpp
+++ b/include/external/clara.hpp
@@ -1,4 +1,4 @@
-// v1.0
+// v1.0-develop.2
 // See https://github.com/philsquared/Clara
 
 #ifndef CATCH_CLARA_HPP_INCLUDED
@@ -409,6 +409,14 @@ namespace detail {
         std::string token;
     };
 
+    inline auto isOptPrefix( char c ) -> bool {
+        return c == '-'
+#ifdef CATCH_PLATFORM_WINDOWS
+            || c == '/'
+#endif
+        ;
+    }
+
     // Abstracts iterators into args as a stream of tokens, with option arguments uniformly handled
     class TokenStream {
         using Iterator = std::vector<std::string>::const_iterator;
@@ -425,7 +433,7 @@ namespace detail {
 
             if( it != itEnd ) {
                 auto const &next = *it;
-                if( next[0] == '-' || next[0] == '/' ) {
+                if( isOptPrefix( next[0] ) ) {
                     auto delimiterPos = next.find_first_of( " :=" );
                     if( delimiterPos != std::string::npos ) {
                         m_tokenBuffer.push_back( { TokenType::Option, next.substr( 0, delimiterPos ) } );
@@ -915,9 +923,11 @@ namespace detail {
     };
 
     inline auto normaliseOpt( std::string const &optName ) -> std::string {
+#ifdef CATCH_PLATFORM_WINDOWS
         if( optName[0] == '/' )
             return "-" + optName.substr( 1 );
         else
+#endif
             return optName;
     }
 
@@ -958,11 +968,7 @@ namespace detail {
         }
 
         auto isMatch( std::string const &optToken ) const -> bool {
-#ifdef CATCH_PLATFORM_WINDOWS
             auto normalisedToken = normaliseOpt( optToken );
-#else
-            auto const &normalisedToken = optToken;
-#endif
             for( auto const &name : m_optNames ) {
                 if( normaliseOpt( name ) == normalisedToken )
                     return true;
@@ -1012,8 +1018,13 @@ namespace detail {
             for( auto const &name : m_optNames ) {
                 if( name.empty() )
                     return Result::logicError( "Option name cannot be empty" );
+#ifdef CATCH_PLATFORM_WINDOWS
                 if( name[0] != '-' && name[0] != '/' )
                     return Result::logicError( "Option name must begin with '-' or '/'" );
+#else
+                if( name[0] != '-' )
+                    return Result::logicError( "Option name must begin with '-'" );
+#endif
             }
             return ParserRefImpl::validate();
         }
diff --git a/third_party/clara.hpp b/third_party/clara.hpp
index 83c4c514..aa429e7a 100644
--- a/third_party/clara.hpp
+++ b/third_party/clara.hpp
@@ -1,4 +1,4 @@
-// v1.0
+// v1.0-develop.2
 // See https://github.com/philsquared/Clara
 
 #ifndef CLARA_HPP_INCLUDED
@@ -409,6 +409,14 @@ namespace detail {
         std::string token;
     };
 
+    inline auto isOptPrefix( char c ) -> bool {
+        return c == '-'
+#ifdef CLARA_PLATFORM_WINDOWS
+            || c == '/'
+#endif
+        ;
+    }
+
     // Abstracts iterators into args as a stream of tokens, with option arguments uniformly handled
     class TokenStream {
         using Iterator = std::vector<std::string>::const_iterator;
@@ -425,7 +433,7 @@ namespace detail {
 
             if( it != itEnd ) {
                 auto const &next = *it;
-                if( next[0] == '-' || next[0] == '/' ) {
+                if( isOptPrefix( next[0] ) ) {
                     auto delimiterPos = next.find_first_of( " :=" );
                     if( delimiterPos != std::string::npos ) {
                         m_tokenBuffer.push_back( { TokenType::Option, next.substr( 0, delimiterPos ) } );
@@ -915,9 +923,11 @@ namespace detail {
     };
 
     inline auto normaliseOpt( std::string const &optName ) -> std::string {
+#ifdef CLARA_PLATFORM_WINDOWS
         if( optName[0] == '/' )
             return "-" + optName.substr( 1 );
         else
+#endif
             return optName;
     }
 
@@ -958,11 +968,7 @@ namespace detail {
         }
 
         auto isMatch( std::string const &optToken ) const -> bool {
-#ifdef CLARA_PLATFORM_WINDOWS
             auto normalisedToken = normaliseOpt( optToken );
-#else
-            auto const &normalisedToken = optToken;
-#endif
             for( auto const &name : m_optNames ) {
                 if( normaliseOpt( name ) == normalisedToken )
                     return true;
@@ -1012,8 +1018,13 @@ namespace detail {
             for( auto const &name : m_optNames ) {
                 if( name.empty() )
                     return Result::logicError( "Option name cannot be empty" );
+#ifdef CLARA_PLATFORM_WINDOWS
                 if( name[0] != '-' && name[0] != '/' )
                     return Result::logicError( "Option name must begin with '-' or '/'" );
+#else
+                if( name[0] != '-' )
+                    return Result::logicError( "Option name must begin with '-'" );
+#endif
             }
             return ParserRefImpl::validate();
         }
@@ -1142,10 +1153,15 @@ namespace detail {
                 size_t count = 0;
             };
             const size_t totalParsers = m_options.size() + m_args.size();
-            ParserInfo parseInfos[totalParsers];
-            size_t i = 0;
-            for( auto const& opt : m_options ) parseInfos[i++].parser = &opt;
-            for( auto const& arg : m_args ) parseInfos[i++].parser = &arg;
+            assert( totalParsers < 512 );
+            // ParserInfo parseInfos[totalParsers]; // <-- this is what we really want to do
+            ParserInfo parseInfos[512];
+
+            {
+                size_t i = 0;
+                for (auto const &opt : m_options) parseInfos[i++].parser = &opt;
+                for (auto const &arg : m_args) parseInfos[i++].parser = &arg;
+            }
 
             m_exeName.set( exeName );
 
@@ -1153,7 +1169,8 @@ namespace detail {
             while( result.value().remainingTokens() ) {
                 bool tokenParsed = false;
 
-                for( auto& parseInfo : parseInfos ) {
+                for( size_t i = 0; i < totalParsers; ++i ) {
+                    auto&  parseInfo = parseInfos[i];
                     if( parseInfo.parser->cardinality() == 0 || parseInfo.count < parseInfo.parser->cardinality() ) {
                         result = parseInfo.parser->parse(exeName, result.value().remainingTokens());
                         if (!result)