zlib 1.5.6 removed from releases

[m-vz]

Output of brew config

HOMEBREW_VERSION: 4.2.15-53-g02a0ea8
ORIGIN: https://github.com/Homebrew/brew
HEAD: 02a0ea84492f07d5d3522ba45958166ec0d5481b
Last commit: 13 hours ago
Core tap JSON: 30 Mar 13:15 UTC
Core cask tap JSON: 30 Mar 13:15 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_EDITOR: nvim
HOMEBREW_MAKE_JOBS: 10
HOMEBREW_SORBET_RUNTIME: set
Homebrew Ruby: 3.1.4 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/bin/ruby
CPU: 10-core 64-bit arm_firestorm_icestorm
Clang: 15.0.0 build 1500
Git: 2.39.3 => /Library/Developer/CommandLineTools/usr/bin/git
Curl: 8.1.2 => /usr/bin/curl
macOS: 13.6.3-arm64
CLT: 15.1.0.0.1.1700200546
Xcode: N/A
Rosetta 2: false

Output of brew doctor

Warning: No Cask quarantine support available: unknown reason.

Description of issue

I'm not familiar with how the distributed version of a brew package is determined, so feel free to close this if it turns out to be irrelevant.

The 1.5.6 release of zlib is not listed on the zlib releases page anymore. There is also a discussion about this here: facebook/zstd#4004

Is the published version of the zlib homebrew package determined from the tag that still exists or from the release?

[SMillerDev]

We'll keep an eye on it, but generally unless it's a known security issue. We wait for upstream to explain why it's gone.

[m-vz]

Thanks, that makes sense.

[ZhongRuoyu]

Upstream have explained why the release was remade in facebook/zstd#4004 (comment). The tag still points to the same commit, and the tarball checksum stays the same. So, nothing will change in homebrew/core.

(The package you're referring to is Facebook's zstd; zlib is a different package.)