Custom environments in subinterpreters

Feature or enhancement

Proposal:

I wanted to explore the viability of having custom environments in subinterpreters. There are several use-cases that could be enabled by this feature.

So far, from informal discussion with others about this, there are a couple possible issues to take into consideration.

Issues

1. Some of the immortal objects shared between subinterpreter may be environment-dependent (pointed out by @Yhg1s)
2. Complications around dynamic loading, by having extension modules from different environments
   2.1) Symbol conflicts from their dependencies (pointed out by @Yhg1s)
   2.2) Since subinterpreters share the same process, when loading the same shared object, they get the same pointer (pointed out by @pablogsal)

Implementation

The main thing we need is a way to disable the site initialization, which could be a enable_site option in the interpreter config. This should disable the environment customizations, and result in a bare environment without anything extra sys.path.

However, to make the use of different environments more ergonomic, we could add an environment_path location pointing to a directory containing a pyvenv.cfg, which would perform the site initialization for that environment.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

該 issue 未指定任何檔案或測試；請先檢視 subinterpreter 的直譯器設定與 site 初始化。根據列出的 immortal-object 與 dynamic-loading 相關疑慮，評估提議的 enable_site 與 environment_path 選項。完成的標準是形成一份經各方同意的設計，解決這些疑慮並定義實作範圍。