when the tmpdir dir is longer than 220, there is no files saved in tmp/sysroots/x86_64-linux/var/lib/apt/lists/ after run apt-get update, this is because apt-get uses the path as the file name, but the file name can't be longer than 255 according to /usr/include/linux/limits.h, here is the related from apt-pkg/contrib/strutl.cc:

string URItoFileName(const string &URI)
{
   // Nuke 'sensitive' items
   ::URI U(URI);
   U.User.clear();
   U.Password.clear();
   U.Access.clear();

   // "\x00-\x20{}|\\\\^\\[\\]<>\"\x7F-\xFF";
   string NewURI = QuoteString(U,"\\|{}[]<>\"^~_=!@#$%^&*");
   replace(NewURI.begin(),NewURI.end(),'/','_');
   return NewURI;
}

Limit the NewURI length to 255 would fix the problem.