azure-cli: crash when handling InvalidTemplateDeployment (response already consumed)

[EMMANUELOBINNAONYEMUCHE]

Title: azure-cli: crash when handling InvalidTemplateDeployment (response already consumed)

Description:
When running az vm create the deployment fails with an ARM error (SkuNotAvailable). While handling the ARM template error the CLI hits an internal exception: "The content for this response was already consumed" which leads to an AttributeError and a RuntimeError. The CLI should surface the ARM inner error instead of crashing while trying to read the consumed response.

Environment:

• OS: macOS
• azure-cli: 2.84.0 (installed via Homebrew)
• Python: 3.13.12
• Command run:

az vm create --resource-group reliabilityLabRG1 --name vm1 --image Ubuntu2204 --admin-username azureuser --generate-ssh-keys

Relevant debug excerpt (tail of ~/az_vm_create_debug.log):

Exception Details:      (SkuNotAvailable) The requested VM size for resource 'Following SKUs have failed for Capacity Restrictions: Standard_DS1_v2' is currently not available in location 'eastus'. Please try another size or deploy to a different location or different zone.
Code: SkuNotAvailable

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File ".../azure/cli/core/commands/arm.py", line 109, in handle_template_based_exception
    raise CLIError(ex.inner_exception.error.message)
                   ^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'error'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File ".../requests/models.py", line 926, in text
    if not self.content:
           ^^^^^^^^^^^^
  File ".../requests/models.py", line 897, in content
    raise RuntimeError("The content for this response was already consumed")
RuntimeError: The content for this response was already consumed

What I expected:

• The CLI should show the ARM inner error (SkuNotAvailable) in a clear, non-failing way and not raise a secondary exception while formatting the message.

Steps to reproduce:

1. Ensure eastus subscription has capacity restrictions for Standard_DS1_v2 (or simulate failure by requesting an unavailable SKU).
2. Run the az vm create command above.
3. Observe that the CLI crashes with a consumed response error while trying to display the template inner error.

Attachments / Logs:

• Full debug log saved at: ~/az_vm_create_debug.log (tail included above)
• az --version output included in the debug log

Suggested fix:

• Guard against None inner_exception or already-consumed response when building CLI error messages; prefer to fall back to the HttpResponseError.message or the JSON body captured earlier.

Please let me know if you want the full az_vm_create_debug.log attached; I can paste it or provide a link.

[yonzhan]

Thank you for opening this issue, we will look into it.

[EMMANUELOBINNAONYEMUCHE]

Full debug log: https://gist.github.com/EMMANUELOBINNAONYEMUCHE/ada0ebba46fb1b6f23a6bedfec7e5637

[github-actions]

Here are some similar issues that might help you. Please check if they can solve your problem.

• Deployment validation fails with 'content already consumed' error #32149
• Errors in "az deployment group create" not helpful #32261

---

Possible solution (Extracted from existing issue, might be incorrect; please verify carefully)

Solution 1:

Use local validation tools as a workaround to avoid the 'content already consumed' error:

# Syntax validation
az bicep build --file template.bicep --stdout > /dev/null

# Best practices check
az bicep lint --file template.bicep

Reference:

• Deployment validation fails with 'content already consumed' error #32149 (comment)

Solution 2:

The issue appears to be a regression in error handling where HTTP response content is being consumed multiple times. The fix should ensure response content is not read more than once, or clone the response before initial consumption.

Reference:

• Deployment validation fails with 'content already consumed' error #32149 (comment)

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