load_dotenv does not work with variables in values

I have a .env file with this variables similar to those explained in the library README:

# Development settings
DOMAIN=example.org
ADMIN_EMAIL=admin@${DOMAIN}
ROOT_URL=${DOMAIN}/app

# base work directory
WORKDIR=/workdir_shared

# logdir
LOGDIR=${WORKDIR}/logs

When I run this script I see that the values of variables ${DOMAIN} and ${WORKDIR} are not applied. I get:

DOMAIN: example.org
ROOT_URL: ${DOMAIN}/app
ADMIN_EMAIL: admin@${DOMAIN}
WORKDIR: /workdir_shared
LOGDIR: ${WORKDIR}/logs

Whe it should be:

DOMAIN: example.org
ROOT_URL: example.org/app
ADMIN_EMAIL: admin@example.org
WORKDIR: /workdir_shared
LOGDIR: workdir_shared/logs

What can be wrong?

This is the script code:

import os
from dotenv import load_dotenv


load_dotenv(verbose=True, interpolate=True)

print("DOMAIN:", os.getenv("DOMAIN"))
print("ROOT_URL:", os.getenv("ROOT_URL"))
print("ADMIN_EMAIL:", os.getenv("ADMIN_EMAIL"))
print("WORKDIR:", os.getenv("WORKDIR"))
print("LOGDIR:", os.getenv("LOGDIR"))

I tried with "load_dotenv()" with same result.

Start by reproducing the issue with the provided .env contents and Python script, then trace load_dotenv's interpolation path. Check how referenced variables are resolved and add coverage for DOMAIN and WORKDIR substitutions; done means the shown ROOT_URL, ADMIN_EMAIL, and LOGDIR values expand as expected.