buffertools.indexOf sometimes returns -1 instead of the expected value for this particular buffer.

buffertools-indexOf.js

var util = require('util'),
    buffertools = require('buffertools'),
    buffer = new Buffer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fromHex();
    
util.log(buffer.indexOf("=yend") + ' (expecting 551)');