Re: [PATCH 1/1] Fix detection of pwritev support for OSX.

On 23.01.2021 08:02, Sergey Shinderuk wrote:
> I checked the script [1], and it really requires the CLT. Here is the 
> explanation [2] for this:
> 
>      There is actually no such requirement. However, there are
>      formulae that will be forced to build from source if you do not
>      have the CLT. They can still be built from source with Xcode
>      only, but because the pre-built bottles are compiled in an
>      environment that has both Xcode and the CLT installed, there are
>      some cases where the bottles end up having a hard dependency on
>      the CLT. A major example is gcc. So installing the CLT may help
>      you avoid some lengthy source builds.
> 
>      We ensure that all Homebrew formulae can be built with Xcode.app
>      alone. Most formulae can be built with just the CLT, and those
>      that require the full Xcode.app have an explicit depends_on
>      :xcode => :build. Some users would prefer to use only the CLT
>      because it's a much smaller download and takes less time to
>      install and upgrade than Xcode.


In the gcc formula [1]:

   # The bottles are built on systems with the CLT installed, and do not 
work
   # out of the box on Xcode-only systems due to an incorrect sysroot.
   pour_bottle? do
     reason "The bottle needs the Xcode CLT to be installed."
     satisfy { MacOS::CLT.installed? }
   end


I guess this is the "xcrun --show-sdk-path" thing we've alredy disccussed :)


[1] https://github.com/Homebrew/homebrew-core/blob/master/Formula/gcc.rb#L36

-- 
Sergey Shinderuk
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