Apparently enabling `xdebug.mode=debug,develop` breaks the proxy generation

[odahcam]

I just discovered this after many hours of debugging, sorry I couldn't get more data but I'm using this @ v1.0.18 with PHP-DI v7.0.8 and I had to test each commit of my app to find out what broke it. Turns out enabling the mode xdebug.mode=debug,develop breaks PHP-DI lazy injections because it can't generate the proxies using this library. I believe xdebug is probably exaggerating some notice or warning and breaking everything afterwards. I understand you might not want to dig into this but I found it was a good idea to document this somewhere in case any unlucky dev falls into this buggy trap. Thanks.