How to install brew using a shallow clone (especially useful in CI systems)

Question

The brew installer does a git clone of some very large repositories, which is slow.

It doesn't use:

• shallow clones because GitHub asked them not to so-as to avoid brew update being slower cf https://github.com/Homebrew/install/issues/541 , and
• partial clones are not supported yet cf https://github.com/Homebrew/brew/issues/13188

In a CI environment where brew update is not needed, how can the brew installer be forced to use a shallow clone to speed up the operation?

Answer 1

The installer can be hacked to use shallow clone. Then an error occurs when the installer tries to run brew update . So the steps are fetch the installer script, force using shallow clone, and remove the use of brew update .

wget -c https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh
sed -i 's:"git" "fetch":"git" "fetch" "--depth" "1":' ./install.sh
sed -i '/"update" "--force"/d' ./install.sh

When doing this, be sure to use HOMEBREW_NO_AUTO_UPDATE=1 and do not use brew update .

To do the install, run

HOMEBREW_NO_AUTO_UPDATE=1 bash ./install.sh