How to download and install an unmerged bottle

[jeroen]

Output of brew config

HOMEBREW_VERSION: 4.6.7-11-g82fabab
ORIGIN: https://github.com/Homebrew/brew
HEAD: 82fabab8aa589b97cf952f0930039e1ee935326d
Last commit: 2 hours ago
Branch: main
Core tap JSON: 25 Aug 09:28 UTC
Core cask tap JSON: 25 Aug 09:28 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DISPLAY: /private/tmp/com.apple.launchd.z5L41KhSWm/org.xquartz:0
HOMEBREW_FORBID_PACKAGES_FROM_PATHS: set
HOMEBREW_MAKE_JOBS: 8
HOMEBREW_SORBET_RUNTIME: set
Homebrew Ruby: 3.4.5 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.4.5/bin/ruby
CPU: octa-core 64-bit arm_blizzard_avalanche
Clang: 17.0.0 build 1700
Git: 2.39.5 => /Library/Developer/CommandLineTools/usr/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 15.6.1-arm64
CLT: 16.4.0.0.1.1747106510
Xcode: N/A
Rosetta 2: false

Output of brew doctor

brew doctor
Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!

Warning: You have the following deprecated, official taps tapped:
  Homebrew/homebrew-services
Untap them with `brew untap`.

Description of issue

I want to test the new version of ffmpeg8 from the pr even though it is not merged yet.

So I downloaded the bottle from the PR artifacts bottles_15-arm64-17171683811-long. But how do I install this bottle? I thought in the past I could just brew install the file name but this no longer seems to work

brew install ./ffmpeg--8.0.arm64_sequoia.bottle.tar.gz
==> Downloading https://formulae.brew.sh/api/formula.jws.json
==> Downloading https://formulae.brew.sh/api/cask.jws.json
Warning: No available formula with the name "ffmpeg--8.0.arm64_sequoia.bottle.tar.gz".

[p-linnane]

HOMEBREW_NO_INSTALL_FROM_API=1 brew install ./ffmpeg--8.0.arm64_sequoia.bottle.tar.gz

[jeroen]

This does not work :(

HOMEBREW_NO_INSTALL_FROM_API=1 brew install ./libxml2--2.15.0.arm64_tahoe.bottle.tar.gz
Warning: No available formula with the name "libxml2--2.15.0.arm64_tahoe.bottle.tar.gz".
==> Searching for similarly named formulae and casks...
Error: No formulae or casks found for libxml2--2.15.0.arm64_tahoe.bottle.tar.gz.

[ZhongRuoyu]

Please try setting HOMEBREW_DEVELOPER=1 too.