Bug: python-dotenv doesn't load 1Password “mounted” .env files (looks like a FIFO / fd-backed file)

Start by reproducing the mounted .env behavior with the named load_dotenv() and dotenv_values() entry points on macOS. Trace how they open and read the supplied path, then verify completion by confirming that key/value pairs from the 1Password-mounted file are loaded rather than an empty string.

I’ve been trying 1Password’s new environment feature which mounts a .env file to a destination path (I think it’s a pipe, file descriptor path, or some other non-regular file). This seems to be a Mac feature right now.

python-dotenv doesn’t seem to load anything from it, even though the path exists.

What I expected

load_dotenv() (or dotenv_values()) should read key/value pairs from the mounted .env file, same as a normal file. I'd expect something similar to Node's dotenv package, that when the file tries to be read, 1Password prompts you to allow access. Only then are the values available

What happened instead

The file path exists, but reading it gives an empty string (and python-dotenv ends up loading nothing).

Quick sanity check:

from pathlib import Path

p = Path(".env")
print("exists:", p.exists())
print("readable:", p.read_text(errors="replace"))

Output:

exists: True
readable:

Repro steps

1. Use 1Password to mount / expose a .env file (however their new environment feature does it).
2. Point the app at that .env path (eg in the project root as .env).
3. Call load_dotenv() or dotenv_values().
4. Observe that nothing is loaded.

Versions

• OS: macOS 15.6
• Python: 3.13
• python-dotenv: 1.0.1
• 1Password + CLI: 8.11.22