dotnet new is slow with 3.0 sdk

dotnet new takes much longer with 3.0 sdk. From less than half a second with 2.2, to more than 3 seconds with 3.0:

$ dotnet --version
2.2.108
$ time dotnet new console --no-restore
The template "Console Application" was created successfully.

real	0m0.416s
user	0m0.395s
sys	0m0.039s

$ dotnet --version
3.0.100-preview8-013656
$ time dotnet new console --no-restore
The template "Console Application" was created successfully.

real	0m3.369s
user	0m0.847s
sys	0m0.070s

The message The template "Console Application" was created successfully. appears as fast, but then the program still idle for some time.

[MykolaBalakin]

@git-Charlie here is the place in the code: https://github.com/dotnet/templating/blob/v3.1.4/src/Microsoft.TemplateSearch.Common/BlobStoreSourceFileProvider.cs#L33

So setting DOTNET_NEW_LOCAL_SEARCH_FILE_ONLY env variable to 1 disables the update check.

But still… The json returned looks like the whole template package list. So it will work slower with every new community project template added (at least because of more data transferred). Is it expected?

BTW. I’m ready to contribute the fix if smbd from the project team confirms the way to improve the tool (@KathleenDollard). Maybe something like checking updates no more than once per day?

[DavidKarlas]

This has been addressed in .NET 6 Preview 4, this are major changes here:

1. We don’t download that 3MB .json anymore but check using NuGet.org API which is much smaller/faster
2. We execute check in parallel with template creation
3. We stopped checking for updates for SDK installed templates(console, web…)

We also plan to add option to disable checking for update.