failed to create file via template error in newer release. what changed??

I have an existing docker compose that is working without issue for some time. Migrated to a new host /docker environment and and spun up my existing compose file. I get the below error in the log fine when trying to start the backup container.

mktemp: failed to create file via template ‘/tmp/tmp.XXXXXXXXXX’: Permission denied

check back on my old environment to see what image I was running and it looks to be 2025.4.0.

if I set 2025.4.0 as my image everything comes up as it should.

I checked the samples https://github.com/itzg/docker-mc-backup/blob/master/examples/docker-compose.yml
and this is basically what I'm running.

so I'm not really sure what changed. (obviously a lot since 2025.4) but the sample docker compose seems to be the same as what I have for the 2025.4 image.

any help would be great,
Thanks,

Start by comparing the 2025.4.0 image with the newer image used by the existing compose setup, using examples/docker-compose.yml as the configuration reference. Investigate the mktemp permission-denied error during backup startup and verify that the container can start and create its temporary file without changing the working compose behavior.

Written by the indexing model from the issue text.