Inform users whether a package supports custom install path

[eugenesvk]

Relevant area(s)

WinGet CLI

Description of the new feature / enhancement

You can choose a custom install path #1213
But it's "advisory"

this has been implemented in the client, but it does depend on the installer having support for the install location.

So would be helpful to know whether an app supports this winget flag or not

Proposed technical implementation details

• Add a field to the app installation manifest that signals whether the capability is supported
• If it's not supported, then installing an app with --location flag should stop with an error (with an option to convert this into just a warning without stopping the installation)
• display this capability in the "winget show app"

[Trenly]

This is already implemented in

• Add support for UnsupportedArguments #2216
• Add the ability to identify unsupported arguments #1277

When a manifest specifies the location argument is not supported, using the parameter will error out

[microsoft-github-policy-service]

Hello @@eugenesvk,

We've identified this as a duplicate of another issue or PR that already exists. This specific instance is being closed in favor of the linked issue. Please add your 👍 to the other issue to raise its priority. Thanks for your contribution!

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[eugenesvk]

I see, it's just almost no app uses that field, hence I thought it wasn't done (I've only found 1(one!) manifest doing that ).
But the last part isn't implemented - there is no info in "winget show", so I can only learn about the lack of explicit support only if I try to install it. This should be added

display this capability in the "winget show app"

Also, given that it's not used much in manifests, can Winget detect some lack of support itself? For example, if msix doesn't support --location unlike msi, then just the fact that the installer is msix should allow Winget to "autofill" that property and show that location is not supported even if the manifest itself doesn't have this info