How to run lit tests on Mac OSX without gcc?

[Johan Engelen via digitalmars-d-ldc]

On Thursday, 31 August 2017 at 10:59:55 UTC, David Nadlinger 
wrote:
> On 30 Aug 2017, at 19:29, Thomas Mader via digitalmars-d-ldc 
> wrote:
>> "config.environmen['CC'] = 'clang'" added to 
>> "tests/lit.site.cfg.in" gets it going. :-)
>
> @Johan: Does this ring a bell – is there something special to 
> be done for lit to just pass through environment variables?

We don't want to pass through all env variables, as it is going 
to disrupt testing in strange ways. I take it as a very good 
thing that Lit does not pass env vars through.

We could pass through specific ones explicitly:
```
   config.environmen['CC'] = os.environ['CC']
```

-Johan