Some environment variable values get capitalized in the container.

[jan-matejka]

% cat compose.yaml
services:
  srv:
    image: docker.io/library/debian:latest
    environment:
      FOO: true
    command: bash
% pc run srv
a66afe21ee47da736df150547cb9d65719755e462415e5357750258e38ed2ccc
root@823fa4a76cdc:/# env |grep FOO
FOO=True
% podman run -e FOO=true -it docker.io/library/debian:latest bash
root@1bc3c5b6c378:/# env | grep FOO
FOO=true

Probably specifically python's bool literals.