Templating: Cannot create netcoreapp1.x templates after installing 2.0 CLI

[natemcmaster]

Installing the 2.0 CLI makes netcoreapp1.x templates inaccessible

Repro
Install .NET Core SDK 1.0.4
dotnet new web --framework netcoreapp1.1. Works 😄

Install .NET Core SDK 2.0.0
dotnet new web --framework netcoreapp1.1.

Expected
The template system sees that both a 1.0 and 2.0 SDK are installed and fallsback to the 1.0 SDK for frameworks the 2.0 SDK doesn't include

Actual

Error: Invalid parameter(s):
--framework netcoreapp1.1
    'netcoreapp1.1' is not a valid value for --framework (Framework).

Workaround
Before invoking dotnet new, create a global.json file and point dotnet to the old version.

{ "sdk": { "version": "1.0.4" }}

[seancpeters]

This is actually by design. The dotnet CLI 2.x does not ship with the 1.x templates because the 2.x CLI does not carry the 1.0/1.1 runtimes. But you can install the 1.x templates on your 2.x CLI install. To install them, add this myget feed to your global NuGet.config: https://dotnet.myget.org/F/templating/api/v3/index.json, and then install the desired template packs using one or more of these commands:

dotnet new -i Microsoft.DotNet.Common.ProjectTemplates.1.x::1.0.0-*
dotnet new -i Microsoft.DotNet.Test.ProjectTemplates.1.x::1.0.0-*
dotnet new -i Microsoft.DotNet.Web.ProjectTemplates.1.x::1.0.0-*

[natemcmaster]

Good to know there is a way to install these templates, though I would never have discovered this on my own. Also, this is rather cumbersome, especially the part where I have to (1) find and (2) edit the global nuget.config file. Could this story be improved?

• Add instructions of installing the old templates to the error message
• Add a --source flag to dotnet new -i so I don't have to find the global NuGet.config file.
• Auto-install the templates when a recognized but not-bundled-by-default target framework is specified.

$ dotnet new web --framework netcoreapp1.1
Error: 'netcoreapp1.1' is not a recognized framework for installed templates.
Would you like to install the templates for 'netcoreapp1.1'? [Y/n]
Y
Installing 'Microsoft.DotNet.Web.ProjectTemplates.1.x::1.0.0-*' from 'https://dotnet.myget.org/F/templating/api/v3/index.json'

[seancpeters]

Good suggestions - I agree, how to install the 1.x templates is not really discoverable.
@mlorbetske @sayedihashimi - any thoughts on how to best convey to the user how to install 1.x templates on the 2.x CLI? This is likely to come up again.

We are discussing / planning a user experience similar to your third suggestion - here: https://github.com/dotnet/templating/issues/1084 - please let us know if you have additional thoughts on what you'd expect / prefer from that sort of functionality. It would also make the need for editing your NuGet.config file unnecessary.

[AnupSingh2008]

In your system higher version of core is available. So to fix the issue type this command
dotnet new mvc --language C# --auth None --framework netcoreapp2.1 and it will work.

Always version which is installed in your system.

[natemcmaster]

My original question was answered. We can use #1084 for follow-up.