WPE (and GTK) Failure looks like this: [668/857] Linking CXX executable bin/WPENetworkProcess FAILED: bin/WPENetworkProcess : && /usr/lib/ccache/c++ -fdiagnostics-color=always -Wno-attributes -Wno-maybe-uninitialized -Wwrite-strings -Wundef -Wpointer-arith -Wmissing-format-attribute -Wformat-security -Wcast-align -Wextra -Wall -fno-strict-aliasing -fno-exceptions -std=c++14 -fno-rtti -O3 -DNDEBUG -L/home/buildbot/wpe/wpe-linux-64-release/build/WebKitBuild/DependenciesWPE/Root/lib -fuse-ld=gold -Wl,--disable-new-dtags Source/WebKit/CMakeFiles/NetworkProcess.dir/NetworkProcess/EntryPoint/unix/NetworkProcessMain.cpp.o -o bin/WPENetworkProcess -Wl,-rpath,/home/buildbot/wpe/wpe-linux-64-release/build/WebKitBuild/Release/lib: -rdynamic lib/libWPEWebKit.so.1.0.0 lib/libWebCore.a lib/libPAL.a lib/libJavaScriptCore.a lib/libWTF.a lib/libbmalloc.a -ldl ../DependenciesWPE/Root/lib/libWPEBackend.so && : lib/libWPEWebKit.so.1.0.0: error: undefined reference to 'non-virtual thunk to WebKit::WebCookieManager::didReceiveMessage(IPC::Connection&, IPC::Decoder&)' lib/libWPEWebKit.so.1.0.0: error: undefined reference to 'WebKit::WebCookieManager::didReceiveMessage(IPC::Connection&, IPC::Decoder&)' The WebCookieManager message handling doesn't seem to be getting generated, even though it appears in the CMakeLists.txt and SourcesWPE.txt/SourcesGTK.txt files.
See <https://build.webkit.org/builders/WPE%20Linux%2064-bit%20Release%20%28Build%29/builds/9314> for a build failure log.
This was fixed here: Committed r229442: <https://trac.webkit.org/changeset/229442>
<rdar://problem/38283714>