I was installing Homebrew on my MacBook Pro (as per the instructions on this page), when the following message popped up:

git-credential-osxkeychain wants to use your confidential information stored in "github.com" in your keychain.
The authenticity of "git-credential-osxkeychain" cannot be verified. Do you want to allow access to this item?
Always Allow | Deny | Allow

The message that popped up while installing Homebrew

  1. Is it normal for this message to appear while installing Homebrew? Why does it need to use my keychain? What is it going to do with it?

  2. Do I have to click 'Allow' for the installation to complete successfully? What will happen if I don't?

  3. If the answer to the previous question is that I have to click 'Allow', what risks do I run doing so? Is there anything I can do to reduce the risks?

macOS Sierra version 10.12.4

  • 1
    Presumably you already have an account at github.com? I didn't, when I first installed brew, and I didn't get this. After install I hit a daily limit of github polls, which brew told me I could avoid by creating a token at github. My guess is brew's install process wants to check keychain for this token. My advice would be: deny, and see what happens. Worst case, you can always reinstall brew.
    – John N
    Commented Apr 9, 2017 at 7:28
  • @JohnN: Thanks. Good advice. I followed your advice, and the installation resumed and concluded, apparently with no problems. I then proceeded to use Homebrew to successfully install the UNIX command line command 'tree'.
    – Evan Aad
    Commented Apr 9, 2017 at 7:37

2 Answers 2


My answer to question 2 ("Do I have to click 'Allow' for the installation to complete successfully? What will happen if I don't?") is - click "deny" and see what happens. The worst that could happen is that you'll have to reinstall Homebrew.

A wee bit of context from my experience in installing Homebrew: when I installed brew I didn't get this pop-up. However, after installing brew I set up a launchd job to brew update once an hour, and I ran into a daily limit which prevented hourly updates. Brew advised me the solution to this was to (a) create an account at Github, and (b) generate a token for brew. My assumption is that you already have an account at Github, and that brew install is checking your keychain for a token. In my experience it's not needed for install, and you can generate a token later if you need one.

  • 5
    This is the correct answer. GitHub has a limit for anonymous access from a single IP in a certain amount of time. The way around this limitation is to make the access not anonymous, for which Homebrew needs access to your GitHub credentials. git-credential-osxkeychain is part of XCode and is a Git helper script that looks up HTTPS user data in the OSX Keychain instead of asking you for it on the command line. If you don't hit the limit, you don't need the credentials. Commented Apr 9, 2017 at 10:38

The following helped:

brew untap homebrew/dupes

You can dig the output of:

brew update -dv

to find the cause, the log flood will stop when the message box pops up.

It was asking for several other taps, but it was sufficient to untap and tap them again to finally get rid of the nasty popup.

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