How do I remove hard coded seeds from the bitcoin source code?
There are a few ways to do it, I personally went into src/net.cpp and commented out the if condition that triggers the lookup starting at line 1266.

// if (addrman.size() == 0 &amp;&amp; (GetTime() - nStart &gt; 60)) {
//     static bool done = false;
//     if (!done) {
//         LogPrintf("Adding fixed seed nodes as DNS doesn't seem to be available.\n");
//         addrman.Add(Params().FixedSeeds(), CNetAddr("127.0.0.1"));
//         done = true;
//     }
// }


Another effective fix was to remove all the encoded seed nodes from the two arrays located in src/chainparamsseeds.cpp