Unable to install formula despite having dependencies

[Aspecky]

Output of brew config

HOMEBREW_VERSION: 4.4.17-41-gd0304b4
ORIGIN: https://github.com/Homebrew/brew
HEAD: d0304b4816e5a0c965030e2415b749b01b007f94
Last commit: 71 minutes ago
Branch: master
Core tap JSON: 23 Jan 17:44 UTC
Core cask tap JSON: 23 Jan 17:27 UTC
HOMEBREW_PREFIX: /Users/mtarrih/homebrew
HOMEBREW_REPOSITORY: /Users/mtarrih/homebrew
HOMEBREW_CELLAR: /Users/mtarrih/homebrew/Cellar
HOMEBREW_CACHE: /tmp/Homebrew
HOMEBREW_CASK_OPTS: ["--appdir=/Users/mtarrih/Applications"]
HOMEBREW_LOGS: /tmp/Homebrew/Logs
HOMEBREW_MAKE_JOBS: 12
HOMEBREW_SORBET_RUNTIME: set
Homebrew Ruby: 3.3.7 => /Users/mtarrih/homebrew/Library/Homebrew/vendor/portable-ruby/3.3.7/bin/ruby
CPU: dodeca-core 64-bit cometlake
Clang: 11.0.0 build 1100
Git: 2.21.1 => /Applications/Xcode.app/Contents/Developer/usr/bin/git
Curl: 7.64.1 => /usr/bin/curl
macOS: 10.15.7-x86_64
CLT: 12.4.0.0.1.1610135815
Xcode: 11.3.1

Output of 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: Your Cellar and TEMP directories are on different volumes.
macOS won't move relative symlinks across volumes unless the target file already
exists. Brews known to be affected by this are Git and Narwhal.

You should set the "HOMEBREW_TEMP" environment variable to a suitable
directory on the same volume as your Cellar.

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/libportaudio.2.dylib
  /usr/local/lib/libportaudio.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/mlx.h
  /usr/local/include/node/*
  /usr/local/include/pa_mac_core.h
  /usr/local/include/portaudio.h

Warning: Unbrewed static libraries 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 static libraries:
  /usr/local/lib/libmlx.a
  /usr/local/lib/libportaudio.a

Warning: You are using macOS 10.15.
We (and Apple) do not provide support for this old version.
It is expected behaviour that some formulae will fail to build in this old version.
It is expected behaviour that Homebrew will be buggy and slow.
Do not create any issues about this on Homebrew's GitHub repositories.
Do not create any issues even if you think this message is unrelated.
Any opened issues will be immediately closed without response.
Do not ask for help from Homebrew or its maintainers on social media.
You may ask for help in Homebrew's discussions but are unlikely to receive a response.
Try to figure out the problem yourself and submit a fix as a pull request.
We will review it but may or may not accept it.


Warning: Your Homebrew's prefix is not /usr/local.

Many of Homebrew's bottles (binary packages) can only be used with the default prefix.
Consider uninstalling Homebrew and reinstalling into the default prefix.
It is expected behaviour that some formulae will fail to build in this unsupported configuration.
It is expected behaviour that Homebrew will be buggy and slow.
Do not create any issues about this on Homebrew's GitHub repositories.
Do not create any issues even if you think this message is unrelated.
Any opened issues will be immediately closed without response.
Do not ask for help from Homebrew or its maintainers on social media.
You may ask for help in Homebrew's discussions but are unlikely to receive a response.
Try to figure out the problem yourself and submit a fix as a pull request.
We will review it but may or may not accept it.


Warning: Your Xcode (11.3.1) is outdated.
Please update to Xcode 12.4 (or delete it).
Xcode can be updated from the App Store.

Description of issue

I am running macOS Catalina and I want to install xdotool, I have no sudo access which is why my homebrew install is entirely in $HOME. For some reason I cant install python3.13 but I can install 3.12, so for packages that require python, I simply download the .rb and change the dependency from 3.13 to 3.12 and that works most of the time. This time I had trouble with mesa, I edited the rb file to depend on 3.12 but it still wants to install python3.13 even tho all the other deps are there. When I go to install with --ignore-dependencies the install fails.

[p-linnane]

Some of mesa's dependencies also depend on Python 3.13. You are running in an unsupported configuration, on an unsupported OS, and attempting to do something that is also not supported. Our official guidance would be to have a separate user account for Homebrew use: https://docs.brew.sh/FAQ#why-does-homebrew-say-sudo-is-bad.

[Aspecky]

Yes my installation is unsupported but it's serving surprisingly well thanks to brew's design.
I already installed mesa's dependencies and I do have a functional python3.12 install, running python3.12 in my shell does execute the interpreter, which is why I dont understand when I do brew install --ignore-dependencies --formula /path/to/mesa.rb it fails to create a venv despite the logs showing this:

python3.12
-m
--some-more-args