Hi, I've downloaded the latest nightly package (r73340) and tried to compile it on RHEL6 on a 64 bit machine with gcc 4.4.4, qt 4.6.2 with WebKitTools/Scripts/build-webkit --qt The error looks like: [...] make[1]: Entering directory `/shared/rhel6/src/WebKit-r73340/WebKitBuild/Release/JavaScriptCore' g++ -c -m64 -pipe -Wall -Wextra -Wreturn-type -fno-strict-aliasing -Wcast-align -Wchar-subscripts -Wformat-security -Wreturn-type -Wno-unused-parameter -Wno-sign-compare -Wno-switch -Wno-switch-enum -Wundef -Wmissing-noreturn -Winit-self -Werror -fno-stack-protector -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -O3 -fvisibility=hidden -fvisibility-inlines-hidden -fPIC -D_REENTRANT -DBUILDING_QT__=1 -DNDEBUG -DBUILDING_QT__ -DBUILDING_JavaScriptCore -DBUILDING_WTF -DQT_NO_DEBUG -DQT_CORE_LIB -I/usr/lib64/qt4/mkspecs/linux-g++-64 -I../../../JavaScriptCore -I/usr/include/QtCore -I/usr/include -I../../../JavaScriptCore -I../../../../WebKit-r73340 -I../../../JavaScriptCore/assembler -I../../../JavaScriptCore/bytecode -I../../../JavaScriptCore/bytecompiler -I../../../JavaScriptCore/debugger -I../../../JavaScriptCore/interpreter -I../../../JavaScriptCore/jit -I../../../JavaScriptCore/parser -I../../../JavaScriptCore/pcre -I../../../JavaScriptCore/profiler -I../../../JavaScriptCore/runtime -I../../../JavaScriptCore/wtf -I../../../JavaScriptCore/wtf/gobject -I/shared/rhel6/src/WebKit-r73340/JavaScriptCore/wtf/symbian -I../../../JavaScriptCore/wtf/unicode -I../../../JavaScriptCore/yarr -I../../../JavaScriptCore/API -I../../../JavaScriptCore/ForwardingHeaders -Igenerated -I../include/QtWebKit -I../../../JavaScriptCore/pcre -I/shared/rhel6/src/WebKit-r73340/WebKitBuild/Release/JavaScriptCore/tmp -I. -I../../../JavaScriptCore -I. -o obj/release/RegexCompiler.o ../../../JavaScriptCore/yarr/RegexCompiler.cpp cc1plus: warnings being treated as errors ../../../JavaScriptCore/yarr/RegexCompiler.cpp: In member function ‘void JSC::Yarr::CharacterClassConstructor::putRange(UChar, UChar)’: ../../../JavaScriptCore/yarr/RegexCompiler.cpp:127: error: comparison between signed and unsigned integer expressions ../../../JavaScriptCore/yarr/RegexCompiler.cpp:133: error: comparison between signed and unsigned integer expressions make[1]: *** [obj/release/RegexCompiler.o] Error 1 make[1]: Leaving directory `/shared/rhel6/src/WebKit-r73340/WebKitBuild/Release/JavaScriptCore' make: *** [sub-JavaScriptCore-make_default-ordered] Error 2 Ciao ciao Ralph