How to avoid formula dependencies being added to $PATH?

[mfschumann]

Additional Info

• I am using Windows Subsystem for Linux

Output of brew config

HOMEBREW_VERSION: 4.4.15
ORIGIN: https://github.com/Homebrew/brew
HEAD: b6fafba4864d65acabf966415e14b2dd86d81e1a
Last commit: 3 days ago
Branch: stable
Core tap JSON: 07 Jan 18:10 UTC
HOMEBREW_PREFIX: /home/linuxbrew/.linuxbrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DISPLAY: :0
HOMEBREW_EDITOR: /usr/bin/nano
HOMEBREW_MAKE_JOBS: 8
Homebrew Ruby: 3.3.6 => /var/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/vendor/portable-ruby/3.3.6/bin/ruby
CPU: octa-core 64-bit skylake
Clang: N/A
Git: 2.47.1 => /bin/git
Curl: 8.9.1 => /bin/curl
Kernel: Linux 6.12.7-200.fc41.x86_64 x86_64 GNU/Linux
OS: Fedora release 41 (Forty One)
Host glibc: 2.40
/usr/bin/gcc: 14.2.1
/usr/bin/ruby: N/A
glibc: N/A
gcc@11: N/A
gcc: N/A
xorg: N/A

Output of brew doctor

Your system is ready to brew.

Description of issue

Hi,

I am currently investigating homebrew on Fedora Silverblue as an alternative to package layering. Mostly homebrew works ok for my use case, but one thing regarding installation of dependencies boggles me. I'll give you an example: I want to install btrbk, a perl script with a handful of dependencies. One of the dependencies (btrfs-progs) pulls in a huge tree of its own dependencies, including systemd and many more other basic tools most of which I already have installed on my system (not via homebrew though).

brew install btrbk now installs all of the recursive dependencies and makes the included binaries available in /home/linuxbrew/.linuxbrew/bin, shadowing the system-installed version of systemctl etc. (because homebrew prepends /home/linuxbrew/.linuxbrew/bin to $PATH).

Is it possible with homebrew to only make the formulae that were explicitely installed by the user, but not their dependencies, available in the $PATH? Nix seems to do that by replacing the binaries by wrapper scripts that dynamically add the dependencies' binaries to $PATH. A simpler solution to avoid shadowing may be to only link explicitely installed binaries into /home/linuxbrew/.linuxbrew/bin, and all dependencies in a different directory that is appended to the $PATH.

Dependency tree for btrbk:

mfschumann/tap/btrbk
├── btrfs-progs
│   ├── e2fsprogs
│   │   └── util-linux
│   │       ├── readline
│   │       │   └── ncurses
│   │       ├── libxcrypt
│   │       ├── ncurses
│   │       ├── sqlite
│   │       │   ├── readline
│   │       │   │   └── ncurses
│   │       │   └── zlib
│   │       └── zlib
│   ├── lzo
│   ├── systemd
│   │   ├── glib
│   │   │   ├── pcre2
│   │   │   │   ├── bzip2
│   │   │   │   └── zlib
│   │   │   ├── python-packaging
│   │   │   ├── [email protected]
│   │   │   │   ├── mpdecimal
│   │   │   │   ├── openssl@3
│   │   │   │   │   └── ca-certificates
│   │   │   │   ├── sqlite
│   │   │   │   │   ├── readline
│   │   │   │   │   │   └── ncurses
│   │   │   │   │   └── zlib
│   │   │   │   ├── xz
│   │   │   │   ├── berkeley-db@5
│   │   │   │   ├── bzip2
│   │   │   │   ├── expat
│   │   │   │   ├── libedit
│   │   │   │   │   └── ncurses
│   │   │   │   ├── libffi
│   │   │   │   ├── ncurses
│   │   │   │   ├── unzip
│   │   │   │   │   └── bzip2
│   │   │   │   └── zlib
│   │   │   ├── dbus
│   │   │   │   └── expat
│   │   │   ├── util-linux
│   │   │   │   ├── readline
│   │   │   │   │   └── ncurses
│   │   │   │   ├── libxcrypt
│   │   │   │   ├── ncurses
│   │   │   │   ├── sqlite
│   │   │   │   │   ├── readline
│   │   │   │   │   │   └── ncurses
│   │   │   │   │   └── zlib
│   │   │   │   └── zlib
│   │   │   ├── libffi
│   │   │   └── zlib
│   │   ├── libcap
│   │   ├── libxcrypt
│   │   ├── lz4
│   │   ├── openssl@3
│   │   │   └── ca-certificates
│   │   ├── util-linux
│   │   │   ├── readline
│   │   │   │   └── ncurses
│   │   │   ├── libxcrypt
│   │   │   ├── ncurses
│   │   │   ├── sqlite
│   │   │   │   ├── readline
│   │   │   │   │   └── ncurses
│   │   │   │   └── zlib
│   │   │   └── zlib
│   │   ├── xz
│   │   └── zstd
│   │       ├── lz4
│   │       ├── xz
│   │       └── zlib
│   ├── util-linux
│   │   ├── readline
│   │   │   └── ncurses
│   │   ├── libxcrypt
│   │   ├── ncurses
│   │   ├── sqlite
│   │   │   ├── readline
│   │   │   │   └── ncurses
│   │   │   └── zlib
│   │   └── zlib
│   ├── zlib
│   └── zstd
│       ├── lz4
│       ├── xz
│       └── zlib
├── mbuffer
└── perl
    ├── berkeley-db@5
    ├── gdbm
    ├── expat
    └── libxcrypt