fix error reporting
fix error reporting

gopherjs/gopherjs,gopherjs/gopherjs,gopherjs/gopherjs,bpowers/gopherjs,jargv/gopherjs,jargv/gopherjs,albrow/gopherjs,gopherjs/gopherjs,albrow/gopherjs,bpowers/gopherjs,albrow/gopherjs,bpowers/gopherjs,jargv/gopherjs,gopherjs/gopherjs