Log spans may not be created when inside of a Flask Error Handler - #172

import instana
import logging
import json
from flask import Flask

app = Flask(__name__)

@app.errorhandler(Exception)
def exception_handler(err):
    app.logger.error(str(err))
    return str(err), 500

@app.route('/health', methods=['GET'])
def health():
    return 'OK'

@app.route('/warning', methods=['GET'])
def warning():
    app.logger.warn('This is a warning')
    return 'warning', 400

@app.route('/error', methods=['GET'])
def error():
    app.logger.error('This is an error')
    return 'error', 500

@app.route('/rerror', methods=['GET'])
def rerror():
    found_it = False
    my_list = None
    for i in my_list:
        if i == 'foo':
            found_it = True

    return found_it


if __name__ == '__main__':
    app.logger.setLevel(logging.INFO)
    app.logger.info('Starting')
    app.run(host='0.0.0.0', port=8080)