PAC support disabled because there is no system implementation

Question

I've recently upgraded my Nexus 4 to Android 4.4. Whilst debugging my app, I discovered message W/chromium(14962): [WARNING:proxy_service.cc(888)] PAC support disabled because there is no system implementation

What does it mean ?

---

Logcat

12-12 17:38:56.726: V/WebViewChromium(14962): Binding Chromium to the main looper Looper{41f91588}
12-12 17:38:56.736: I/chromium(14962): [INFO:library_loader_hooks.cc(112)] Chromium logging enabled: level = 0, default verbosity = 0
12-12 17:38:56.736: I/BrowserProcessMain(14962): Initializing chromium process, renderers=0
12-12 17:38:56.746: W/chromium(14962): [WARNING:proxy_service.cc(888)] PAC support disabled because there is no system implementation

Answer 1

I think you can safely ignore this one. It is kinda hard-coded in Chromium Browser Engine.

If you check Chromium sources (https://chromium.googlesource.com/chromium/src.git/+/master/net/proxy/proxy_service.cc) and see ProxyService::CreateUsingSystemProxyResolver you will find

if (!ProxyResolverFactoryForSystem::IsSupported()) {
  LOG(WARNING) << "PAC support disabled because there is no "
                "system implementation";
  return CreateWithoutProxyResolver(proxy_config_service, net_log);
}

where ProxyResolverFactoryForSystem::IsSupported() is just returning false if you're not on Windows or MacOS

class ProxyResolverFactoryForSystem : public ProxyResolverFactory {
  //[...]
  static bool IsSupported() {
#if defined(OS_WIN) || defined(OS_MACOSX)
    return true;
#else
    return false;
#endif
  }
};