Regression in 2.57.0: `vpc private-network list` fails with "bad region format"

[aginhoux]

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Command attempted

scw vpc private-network list vpc-id=<VPC_UUID>

Expected Behavior

The command should return the list of private networks attached to the specified VPC.

Actual Behavior

The command fails with:

{"error":"scaleway-sdk-go: could not parse application/json response body: scaleway-sdk-go: bad region format, available regions are: fr-par, nl-ams, pl-waw, it-mil"}

The issue occurs both with and without -o json.

The same error occurs when explicitly setting the region:

SCW_DEFAULT_REGION=fr-par scw vpc private-network list vpc-id=<VPC_UUID>

Regression

The same command works correctly with CLI 2.56.3 and fails after upgrading to 2.57.0.

More info

Failing version

Version          2.57.0
BuildDate        2026-06-15T11:34:40Z
GoVersion        go1.26.4
GitBranch        HEAD
GitCommit        ff49623d
GoArch           amd64
GoOS             linux
UserAgentPrefix  scaleway-cli

Working version

Working version
Version          2.56.3
BuildDate        2026-06-09T10:18:17Z
GoVersion        go1.26.4
GitBranch        HEAD
GitCommit        94a66f7a
GoArch           amd64
GoOS             linux
UserAgentPrefix  scaleway-cli

Configuration

...
default_region: fr-par
default_zone: fr-par-1

Additional observations

Using the -D debug flag:

• The API request succeeds and returns a 200 OK response.
• The response body contains 4 entries in private_networks.
• All returned private_networks[*].region values are set to fr-par.
• Despite the successful API response, the command fails with a bad region format parsing error.
• The issue is reproducible on every execution.

[mauritsderuiter95]

Same regression here (nl-ams). The field that fails isn't private_networks[*].region (those are populated, which is why they look fine) — it's subnets[*].region, which the API returns as an empty string:

"subnets":[ {"subnet":"172.16.0.0/22", ..., "region":""} ],
"region":"nl-ams"

What changed: 2.57.0 added a Region scw.Region field to the VPC v2 Subnet struct (the "add support for region in private-networks" change in scaleway-sdk-go). 2.56.3 didn't have that field, so it ignored subnets[*].region entirely.

Now the SDK tries to parse it, and an empty string isn't a valid region. Region.UnmarshalJSON rejects "" with bad region format, and that one field aborts decoding the whole (otherwise valid, HTTP 200) response.

The same failure hits scw instance server get on a server with a private NIC, since it calls GetPrivateNetwork internally.

[remyleone]

I think a fix was deployed today, can you check again and see if it still raising this issue. If so, could you provide a minimal snippet of code that reproduce the issue?

[mauritsderuiter95]

Hi @remyleone, I can confirm it is working as expected now.

[remyleone]

Perfect thanks a lot :-)