Document VS Code specific variables that are supported in settings

[dreamflow]

in vscode settings.json :
"ruff.configuration" accepts env-vars independent of lower case or uppe case
"ruff.configuration": "${path_to_ruff_toml}",
this is consistent to env-var access of all other non-ruff settings
in vscode settings.json and windows env-var access in general ,
because env-var-names are case insensitive in windwos .

but "ruff.interpreter" accepts env-vars surprisingly only in all upper case
"ruff.interpreter": [ "${env:PATH_TO_PYTHON_EXE}" ],
but not(!) in lower case (doesn't work) :
"ruff.interpreter": [ "${env:path_to_python_exe}" ],

could please :

• the "ruff.interpreter" setting be improved to accept env-vars
  independent of lower case or upper case of the env-var-name .
• both settings "ruff.interpreter" and "ruff.configuration"
  be improved to support the same env var access syntaxes
  ${env: ... } and ${ ... } . maybe the ${ ... } syntax could later be
  deprecated , in favour of the descriptive/explicit ${env: ... } .
  at present it's either or , meaning currently "ruff.configuration"
  supports exclusively only the ${ ... } syntax and "ruff.interpreter"
  supports exclusively only the ${env: ... } syntax .

my environment :

• ruff-vscode exetension version 2025.22.0
• vscode 64bit portable 1.99.3
• Win10 64bit enterprise 22H2

[dhruvmanila]

The ruff.interpreter setting is specific to the VS Code extension which is why it's listed under "VS Code specific" section. Now, VS Code's variable substitution uses the ${...} syntax (https://code.visualstudio.com/docs/reference/variables-reference#_environment-variables) which is why ruff.interpreter also uses that.

On the other hand, the ruff.configuration is not specific to an editor but is part of the language server. But, it also accepts VS Code specific variables and so it would go through two variable expansions (1) via the extension which would use VS Code specific syntax and (2) via the language server which would use the normal shell environment variable syntax which could be $HOME or ${HOME}.

Does that help? I think it makes sense to document the variables that are supported from the ones that are mentioned here as not all of them are supported.

[dreamflow]

Does that help?

yes . now it's understandable .

is it a bug , that the "ruff.interpreter" settings exclusively
only supports the ${env:ENV_VAR_NAME} syntax ?

the ${ENV_VAR_NAME} syntax and $ENV_VAR_NAME syntax
don't work with the "ruff.interpreter" setting .

[dhruvmanila]

No, it's not a bug. As mentioned, the ruff.interpreter setting is VS Code only so it uses the syntax as mentioned in the docs: https://code.visualstudio.com/docs/reference/variables-reference#_environment-variables and not any other syntax.