Small fixes to the Contributing.txt (#63385)

Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/63385

Correcting a mistake for the pytorch uninstall, and
adding an extra note for Darwin.

Test Plan: Imported from OSS

Reviewed By: janeyx99, heitorschueroff

Differential Revision: D30530234

fbshipit-source-id: e0f88a1725eeadabfb4b28c1da11e369ee878ab4

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 7cf3aec..93de9b0 100644 (file)
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -87,7 +87,7 @@ lazy.)
 
 
 ```bash
-conda -y uninstall pytorch
+conda uninstall pytorch -y
 yes | pip uninstall torch
 ```
 
@@ -781,6 +781,8 @@ If you are editing a single file and rebuilding in a tight loop, the time spent
 linking will dominate. The system linker available in most Linux distributions
 (GNU `ld`) is quite slow. Use a faster linker, like [lld](https://lld.llvm.org/).
 
+People on Mac, follow [this guide](https://stackoverflow.com/questions/42730345/how-to-install-llvm-for-mac) instead.
+
 The easiest way to use `lld` this is download the
 [latest LLVM binaries](http://releases.llvm.org/download.html#8.0.0) and run:
 ```