bug: asdf install returns error for system version

[rnestler]

Describe the Bug

When having configured some tools to use the system versions, asdf install will report an error and return an exit code.

Steps to Reproduce

1. Set a version to system in ~/.tool-versions
2. Run asdf install

Expected Behaviour

Just state that the system version is available.

Actual Behaviour

It shows the error message and returns an error code:

$ asdf install
uninstallable version: system
$ echo $?
1

Environment

OS:
Linux renovigi 6.14.1-arch1-1 #1 SMP PREEMPT_DYNAMIC Mon, 07 Apr 2025 19:59:13 +0000 x86_64 GNU/Linux

SHELL:
zsh 5.9 (x86_64-pc-linux-gnu)

BASH VERSION:
5.2.37(1)-release

ASDF VERSION:
0.16.7-arch

ASDF INTERNAL VARIABLES:
ASDF_DEFAULT_TOOL_VERSIONS_FILENAME=.tool-versions
ASDF_DATA_DIR=/home/raphael/.asdf
ASDF_CONFIG_FILE=/home/raphael/.asdfrc

ASDF INSTALLED PLUGINS:
elixir    https://github.com/asdf-vm/asdf-elixir.git      fb53c458d2d97d7f191482937b2e308a4400741f
erlang    https://github.com/asdf-vm/asdf-erlang.git      5868e8a7a7b1f69be4aa14a76ed5a6c222d9114d
flutter   https://github.com/oae/asdf-flutter.git         bd28847e2b6b4012a461520dd6d7a56296f74e86
java      https://github.com/halcyon/asdf-java.git        6c4dc6b280f6629d9602d7461ed6a5f77054b502
nodejs    https://github.com/asdf-vm/asdf-nodejs.git      fd2c7f94c4c71416047cacf2af6e4fa819b364b7
pnpm      https://github.com/jonathanmorley/asdf-pnpm.git 0de43774f3f249b1ad2cb4bb1a6dc9374c7b143d
python    https://github.com/danhper/asdf-python.git      a3a01856098d6d2b9642e382f5b38e70275726d1
ruby      https://github.com/asdf-vm/asdf-ruby.git        c9c0d271b41ba36b2c9d699f3f84e36acebceb01
yarn      https://github.com/twuni/asdf-yarn.git          376c5407ef22c82fa56e4bd9f6a9108354063acb```

### asdf plugins affected (if relevant)

All.

[scalp42]

Can confirm, system is not allowed anymore (just updated from 0.15.x to 0.16.3).

[unitof]

With system deprecated, is there any way to have asdf to fall back to my PATH (in my case, Homebrew) for a given comment if the local directory does not specify a .tool-versions?

[gunzy83]

With system deprecated, is there any way to have asdf to fall back to my PATH (in my case, Homebrew) for a given comment if the local directory does not specify a .tool-versions?

system is not deprecated, you can still add it to .tool-versions with asdf set and then set will fall through to the system version. This is definitely a bug though in the asdf install command. I have system versions set in my home directory .tool-versions and my dotfiles install script fails because of this.