Nondeterministic unittest debugging problem.

[Rekel via Digitalmars-d-learn]

I am unsure where to mention this as I am utterly lost as to what 
the issue is, which I can simply best describe with 2 
screenshots. Though I'll first give a short description.

For some reason my debugger is "\<Unable to read memory\>" for 
one of my variables in one of my unittests. This is however not 
the case when a random unused variable is inserted in front of 
it. (For reference I'm building the unittest using something 
similar to `dub build --build=unittest --config=unittest --force 
--archType=x86_64`, though the project is a library thus there 
are some complications: 
https://github.com/dlang/dub/issues/1856#issuecomment-899022431)

Not readable:
![](https://www.dropbox.com/s/j6bt3gaxu05om2j/Fout.png?dl=0&raw=1)
Readable:
![](https://www.dropbox.com/s/lnj3ugmuoh339oi/Fout2.png?dl=0&raw=1)

```d
int x = 0;
Mat!(3, 3, float) a = Mat!(3, 3, float)([1, 2, 3, 4, 5, 6, 7, 8, 
9]);
```

Note the x variable is entirely unused while Mat is a struct of a 
union that is essentially just a 2d array of floats.

I have no more clue where to look as I have no clue what could 
cause this, am I overlooking something trivial? Thanks in advance.