Do you want to request a _feature_ or report a _bug_?
Bug
What is the current behavior?
Running yarn self-update outputs the following error:

If the current behavior is a bug, please provide the steps to reproduce.
Run yarn self-update with yarn installed trough piped shell script
What is the expected behavior?
No error when running self-update
Please mention your node.js, yarn and operating system version.
v.6.8.0, v0.15.1, macOS Sierra
me too.
it was installed by brew.
Same here, installed via npm on a Windows machine 👍
I had the same error with v0.15.1, and could just now (a minute ago) perform brew update; brew upgrade to install yarn 0.16.0, and now it seems to work:
$ yarn self-update
yarn self-update v0.16.0
success Yarn is already using the latest version.
✨ Done in 0.61s.
after brew update, brew upgrade:
MacBook ~> yarn self-update
yarn self-update v0.16.0
success Yarn is already using the latest version.
✨ Done in 0.92s.
if it is installed with a brew, you will not be able to self-update?
I can't do that on Windows. Any leads ? Should I install yarn all over again to update ? 😕
The identical bug was already filed #612 and already fixed #676
npm install -g yarn --update updated yarn for me to v0.16.1 and it seems to be fixed. Mine was installed using npm :)
@mbeaudru I had the same issue, in case you installed Yarn via MSI, remove it and everything should work fine.
We'll be removing self-update in the future, please use the update mechanism provided by your installation method.