# RustProxy 0.27.2 implementation note

## Scope

0.27.2 is a focused ACME runtime repair. It keeps SQLite schema 8 and the saved configuration format unchanged.

## Managed Certbot relocation bug

0.27.1 creates the private environment under `<data-dir>/acme-python.installing`, installs Certbot and its DNS plugins there, validates it, and then atomically renames the directory to `<data-dir>/acme-python`.

Python virtual-environment console scripts created by pip contain an absolute interpreter path in their shebang. After the directory rename, `bin/certbot` can still point at the removed `acme-python.installing/bin/python`. Executing that console script can therefore fail with a local `OSError`; the private worker intentionally reduced such errors to `acme.local_io_or_json_error`, which hid the relocation detail from the UI.

## Repair

Managed-environment validation now runs Certbot as:

```text
<data-dir>/acme-python/bin/python -I -m certbot --version
```

ACME issuance and renewal use the same final interpreter with `-m certbot`. The provider worker receives the managed interpreter path from RustProxy and no longer depends on the relocated pip console-script shebang.

The existing system/distribution Certbot fallback continues to execute its discovered `certbot` program normally.

## Upgrade behavior

No ACME profile, account, certificate or credential migration is required. An `acme-python` environment created by 0.27.1 can be reused as-is because 0.27.2 bypasses the stale console-script shebang and imports Certbot from the environment's installed Python modules.