Silent error when using hashmap

[FatalCatharsis via Digitalmars-d]

On Thursday, 27 July 2017 at 00:48:48 UTC, ketmar wrote:
> FatalCatharsis wrote:
>
>> On Thursday, 27 July 2017 at 00:34:28 UTC, ketmar wrote:
>>> wrap the whole event handler function in `try/catch` block, 
>>> and print it there. after all, this is what Dmain does, and 
>>> so can you. having *full* stack trace has no sense there 
>>> anyway, as you know for sure that event handler is called by 
>>> windows, not by you (and usually from your event loop anyway, 
>>> so detailed stack trace has little useful info).
>>
>> I tried that like so:
>>
>> https://gist.github.com/FatalCatharsis/39c5f35ae78ecd5399eebe0fb2491004
>>
>> I put exception blocks both around main and around the 
>> invocation of the hash lookup and still get no printouts 
>> anywhere, including at the beginning and end of main.
>
> 'cause you never printed anything.

the writeln("start"); and writeln("end"); in main. This is what I 
meant by printing. These do not appear in the output. The 
programs starts and immediately ends without printing "start" and 
"end". I did not put an output in the exception handler of the 
WndProc because writeln can throw and the function is marked 
nothrow. All I as trying to do there was get it to recover.