Generating .di header files from ImportC files

[d007]

On Monday, 23 October 2023 at 12:43:24 UTC, jmh530 wrote:
> On Monday, 23 October 2023 at 00:41:58 UTC, Walter Bright wrote:
>> On 10/22/2023 4:45 PM, jmh530 wrote:
>>> Sorry but I don’t think I’ve ever used .di files. What is the 
>>> significance of this?
>>
>> .di files serve the same purpose as .h files do in C.
>
> Looks like the documentation on them has been improved too 
> since the last time I looked at it:
>
> https://dlang.org/dmd-windows.html#interface-files

try on osx: dmd, ldc2, ldmd2.  all get this error:

Error: unrecognized file extension h