`"region"` field on alias config is not respected

[OrkhanAlikhanov]

I have the following config file:

{
	"version": "10",
	"aliases": {
		"remove-s3": {
			"url": "https://somehost.com",
			"accessKey": "CS4osdKrJJzPh8xR",
			"secretKey": "1s6tBBeAd9TovmwISa1fFQSu",
			"api": "S3v4",
			"path": "auto",
                         "region": "us-west-1" // not respected
		}
	}
}

The "region": "us-west-1" line does not have any effect.

Expected behavior

It should create minio client instance with that region set

Actual behavior

The field is ignored.

Steps to reproduce the behavior

mc cp --debug ./index.html remote-s3/my-bucket/example/

The internal s3 compatible service that I'm trying the mc tool to copy some data does not implement the API for fetching bucket details to determine the region, so I was getting 501. I defined "region" in the config.json so that it doesn't fetch bucket information itself, but it didn't have any effect. While this is not the problem of mc but it would be nicer if mc tool passed the region field down to minio client.

Checking the source code I noticed that MC_REGION or AWS_REGION environment variables can be set to achieve what I wanted. I did not find those in docs though.

mc --version

mc version RELEASE.2025-08-13T08-35-41Z (commit-id=7394ce0dd2a80935aded936b09fa12cbb3cb8096)
Runtime: go1.24.6 darwin/arm64

System information

N/A