[Issue 24584] [phobos] `make unittest` should not rerun tests unnecessarily

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=24584

kinke <kinke at gmx.net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kinke at gmx.net

--- Comment #2 from kinke <kinke at gmx.net> ---
(In reply to Nick Treleaven from comment #1)
> But regardless it would be useful if there was a way to run an
> individual module's unittests rather than have to rerun the ones that
> already succeeded.

There are multiple existing options for running the unittests of a single
module or package, all based on
https://github.com/dlang/phobos/blob/ad9f87d1b816783bd8c13f461490e68f7fcae20a/Makefile#L431-L448:

```
$ make -j$(nproc) std/algorithm/mutation.test # single module
$ make -j$(nproc) std/algorithm.test # whole package
$ make -j$(nproc) unittest/std/algorithm/mutation.run # single module
```

That said, *running* (not building) all Phobos unittests on my laptop takes
about 6 (release) / 7.5 (debug) seconds, using current master.

--