AZ-400 Cache NuGet packages Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Use the Cache@2 task with key: 'nuget | "$(Agent.OS)" | packages.lock.json', path: '$(System.DefaultWorkingDirectory)/packages'

  Why this is correct

  The Cache@2 task is the correct built-in mechanism for caching NuGet packages in Azure Pipelines. The composite key, combining 'nuget', the agent OS, and packages.lock.json, invalidates the cache only when the OS or the lock file changes, ensuring restore artifacts are reused across runs. The path points to the packages folder (typically the global packages folder) so subsequent restore operations can use the cached packages without hitting the network.

• ✗

  Use the NuGetCommand@2 task with the -Cache argument.

  Why it's wrong here

  NuGetCommand@2 does not support a '-Cache' argument. The task wraps NuGet CLI commands and accepts arguments for restore, pack, or push, but package caching is not a built-in feature of that task, so this option is invalid.

• ✗

  Set the NUGET_PACKAGES environment variable to a custom path and rely on pipeline caching plugin.

  Why it's wrong here

  The NUGET_PACKAGES environment variable only redirects the NuGet global packages folder to a custom path; it does not by itself cause caching between pipeline runs. Azure Pipelines does not have a native 'pipeline caching plugin' that automatically persists arbitrary environment-variable-defined folders without an explicit Cache task, so relying on that alone would not provide durable cache restoration across separate pipeline executions.

• ✗

  Use the DotNetCoreCLI@2 task with the --no-restore flag and manually copy packages.

  Why it's wrong here

  The DotNetCoreCLI@2 task with the --no-restore flag skips the restore phase entirely, meaning packages would not be restored during the build. Manually copying packages afterward is not an automated caching strategy and would require custom scripting to save and restore the folder, making it an inefficient and error-prone approach compared to Cache@2.

Option-by-option analysis

Why each answer is right or wrong

Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The AZ-400 exam frequently reuses these exact scenarios with slightly different constraints.

Analysis generated from the official AZ-400blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”