On 7/1/21 10:56 AM, Keivan Shah wrote:
Using the handler I was able to get the stack trace and it seems that
the segFault is caused by `joiner` trying to call `.save` on a null
object leading to a `NullPointerError`. But I have not been able to
debug it further. Mostly it seems that there is something wrong with my
understanding of ranges or it could be a genuine bug in std.range.
Can anyone help me debug this piece of code?
Thanks for the detailed instructions, very easy to reproduce.
However, chunkBy is a hot mess, which probably has a bug in it
somewhere. I don't exactly know where this is, but know that using
objects for forward ranges is bound to result in some failures, simply
because they are one of the only forward ranges that *requires* calling
`.save`, and much code exists that forgets to do that.
I spent about 20 minutes trying to find this and can't see how `chunkBy`
actually works in this case. I don't have any more time to spend on it,
sorry.
I narrowed your code down to the minimal case that I could find that
segfaults:
```d
ForwardRange!int[] listOfRanges = [iota(1).inputRangeObject];
auto lazyFlattenedRange = joiner(listOfRanges);
auto d2 = lazyFlattenedRange.chunkBy!(a => a);
while(!d2.empty)
d2.popFront;
```
I hope this helps someone narrow it down.
-Steve
