Why did installing weasyprint upgrade mariadb?

[cbfiddle]

Output of brew config

HOMEBREW_VERSION: 4.3.21
ORIGIN: https://github.com/Homebrew/brew
HEAD: c5d09b411776547bdbc8e0435deaf690ca632413
Last commit: 4 days ago
Core tap JSON: 16 Sep 14:33 UTC
Core cask tap JSON: 16 Sep 14:33 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_MAKE_JOBS: 10
Homebrew Ruby: 3.3.4 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.3.4_1/bin/ruby
CPU: 10-core 64-bit arm_blizzard_avalanche
Clang: 15.0.0 build 1500
Git: 2.39.3 => /Applications/Xcode.app/Contents/Developer/usr/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 15.0-arm64
CLT: 16.0.0.0.1.1723780521
Xcode: 15.4
Rosetta 2: false

Output of brew doctor

Warning: Some installed casks are deprecated or disabled.
You should find replacements for the following casks:
  wkhtmltopdf

Warning: Some installed formulae are deprecated or disabled.
You should find replacements for the following formulae:
  openssl@1.1

Warning: Unbrewed dylibs were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae and may need to be deleted.

Unexpected dylibs:
  /usr/local/lib/libwkhtmltox.0.12.6.dylib

Warning: Unbrewed header files were found in /usr/local/include.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae and may need to be deleted.

Unexpected header files:
  /usr/local/include/jnu.h
  /usr/local/include/wkhtmltox/image.h
  /usr/local/include/wkhtmltox/pdf.h

Warning: Homebrew's "sbin" was not found in your PATH but you have installed
formulae that put executables in /opt/homebrew/sbin.
Consider setting your PATH for example like so:
  echo 'export PATH="/opt/homebrew/sbin:$PATH"' >> ~/.profile

Warning: Your Xcode (15.4) at /Applications/Xcode.app is too outdated.
Please update to Xcode 16.0 (or delete it).
Xcode can be updated from the App Store.

Description of issue

When I installed weasyprint, it upgraded mariadb. I'm trying to understand why that happened. The command output says that mariadb is a dependency of an upgraded formula, but I cannot figure out what the dependency is.
I tried brew deps --include-build --include-test --include-optional weasyprint but mariadb is not in the list.
I tried brew uses --eval-all --recursive --include-build --include-test --include-optional mariadb but it only listed qt-mariadb, which is not installed.
What am I missing?

[carlocab]

What probably happened is that installing weasyprint upgraded another formula (likely one of weasyprint's dependencies, as shown by brew deps weasyprint) that mariadb itself depends on. That is, weasyprint and mariadb share common dependencies. You can view which these are with brew deps weasyprint mariadb.

[cbfiddle]

Thank you, that explains it. There are two shared dependencies that were updated.
May I suggest that the command output could be clearer on this point?
It said:

==> Upgrading 7 dependents of upgraded formulae:
Disable this behaviour by setting HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK.

The help for install is also unclear on this point.

Unless HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK is set, brew upgrade or brew
reinstall will be run for outdated dependents and dependents with broken
linkage, respectively.

The word "dependents" seems to mean something broader than the standard meaning.

[carlocab]

The word "dependents" seems to mean something broader than the standard meaning.

I don't quite follow.

==> Upgrading 7 dependents of upgraded formulae:
Disable this behaviour by setting HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK.

This seems accurate, given:

There are two shared dependencies that were updated.

But we're happy to review PRs to make the messaging clearer here.