131763 2014-04-16 14:37:55 -0700 Startup crash, OSX 10.8.3 2014-05-06 09:35:05 -0700 1 1 1 Unclassified WebKit WebKit API 528+ (Nightly build) Mac (Intel) OS X 10.8 RESOLVED INVALID P2 Critical --- 1 webkitbug webkit-unassigned ap jujjyl oldest_to_newest 1001339 0 webkitbug 2014-04-16 14:37:55 -0700 Symbol not found: _OBJC_CLASS_$_WebSerializedJSValue It appears this was removed from the build: https://bugs.webkit.org/show_bug.cgi?id=128720 1006914 1 jujjyl 2014-05-06 04:45:39 -0700 I can also reproduce this. On OS X 10.8.4, I ran > svn checkout https://svn.webkit.org/repository/webkit/trunk WebKit > cd WebKit > Tools/Scripts/build-webkit (printed ** BUILD SUCCEEDED ** without errors) > Tools/Scripts/run-safari and the result is Starting SafariForWebKitDevelopment with DYLD_FRAMEWORK_PATH set to point to built WebKit in /Users/jjylanki/WebKit/WebKitBuild/Release. dyld: Symbol not found: _OBJC_CLASS_$_WebSerializedJSValue Referenced from: /System/Library/PrivateFrameworks/Safari.framework/Versions/A/Safari Expected in: /Users/jjylanki/WebKit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit in /System/Library/PrivateFrameworks/Safari.framework/Versions/A/Safari Are there any workarounds or fixes known to this? 1006975 2 ap 2014-05-06 09:35:05 -0700 Please install latest OS X and latest released Safari, WebKit nightlies don't work with Safari 6.0.x.