Finding the file and unittest that triggers an ICE during dub project build only when unittests are enabled

[MoonlightSentinel]

On Monday, 15 June 2020 at 10:54:47 UTC, Per Nordlöw wrote:
> What have I missed?

My mistake, dub dustmite expects a path to an temporary directory 
suitable for dustmite (it copies the entire projet + all 
dependencies s.t. dustmite sees the entire source code). That 
path needs to be somewhere outside of the project directory.

But "dub dustmite ..." failed the first tests so I've reduced 
this manually by determining the correct compiler invocation (dub 
test -v) and running dustmite against all (remaining) source 
files. The test condition was a script which ran dmd in gdb and 
checked whether it segfaulted at the specific line of code.

The segfault happens when compiling CyclicArray with 
preview=dtorfields, see the bug report below for a reduced 
example.

TLDR: Found your bug and reported it here:
https://issues.dlang.org/show_bug.cgi?id=20934