...impressed by the support of D in gdb.

Apologies for misreading here!

I am the...

AFAIK with LDC (so debug info are generated with LLVM) there's no way to...

Use gdb; unless you’re running macOS, in which case use the version of lldb included...

...on a D forum.

I am using GDB on Linux, from Windows, trough WSL.
I...

...Does anyone know why?

I've used GDB and here is the message:
Program received...

...instruction (core dumped)
----

The core dump shows:
----
(gdb) bt
#0  0x00007f240dc519dd in _d_criticalenter2 () from...

- in the json, try `dflags-ldc2` instead of `dflags`
- try not to use the debug...

The dub build with --verbose option generates the output
```
Generating using build
Configuring dependent testd1...

...O0", "-d-debug"]
}
```

has NO debug symbols. gdb reports
```
Reading symbols from ./testd1.exe...
(No...

...DefinedType.Defined)
{
}

void main()
{
    f!(int)();
}
```

A gdb backtrace repeats the following three lines:
```
#50...