"The 'NEXT_PUBLIC_API_URL' variable is not set." warning during build; ui/.env NEXT_PUBLIC_API_URL not reflected

[CHANTXU64]

🐛 Describe the bug

I edited ui/.env to set NEXT_PUBLIC_API_URL as described in the quickstart

Reproduction steps:

1. cd /opt
2. sudo git clone https://github.com/mem0ai/mem0.git
3. cd mem0/openmemory
4. sudo make env
5. sudo -e ui/.env

NEXT_PUBLIC_API_URL=https://mem0-api.mydomain.com
NEXT_PUBLIC_USER_ID=mcps

6. sudo -e api/.env

OPENAI_API_KEY=sk-xxx
USER=mcps

7. sudo make build

docker compose build
WARN[0000] The "NEXT_PUBLIC_API_URL" variable is not set. Defaulting to a blank string.
WARN[0000] Docker Compose is configured to build using Bake, but buildx isn't installed
[+] Building 39.2s (38/38) FINISHED
......

8. sudo make up

NEXT_PUBLIC_USER_ID=root NEXT_PUBLIC_API_URL=http://localhost:8765 docker compose up