pgweb 0.16 deprecated `DATABASE_URL` in favour of
`PGWEB_DATABASE_URL`. With the old name, the container starts up,
emits a `[DEPRECATION]` warning, then crashes:
Error: Invalid URL. Valid format:
postgres://user:password@host:port/db?sslmode=mode
— because the new code path reads `PGWEB_DATABASE_URL` (empty)
and the URL parser rejects an empty string.
Rename the env key in the compose file. Same value, just the new
name.
Julien Gautier