Homebrew install specific version of formula?

Question

How do I install a specific version of a formula in homebrew? For example, postgresql-8.4.4 instead of the latest 9.0.

Answer 1

Currently the old ways of installing specific formula versions have been deprecated. So it seems like we have to use brew edit [formula]. E.g. say we want to install an the 62.1 version of icu4c (needed e.g. for postgresql 10.5). Then you'd have to

> brew edit icu4c
# drops you to editor

Here you'd have to alter the url, version and sha256 (perhaps also mirror) to the corresponding 62.1 strings.

url "https://ssl.icu-project.org/files/icu4c/62.1/icu4c-62_1-src.tgz"
mirror "https://github.com/unicode-org/icu/releases/download/release-62-1/icu4c-62_1-src.tgz"
version "62.1"
sha256 "3dd9868d666350dda66a6e305eecde9d479fb70b30d5b55d78a1deffb97d5aa3"

then run brew reinstall icu4c to finally download the 62.1 version.