The specified framework 'Microsoft.NETCore.App', version '1.0.0' was not found

I knew this day would come...

$ dotnet YourFirstProduct.dll
The specified framework 'Microsoft.NETCore.App', version '1.0.0' was not found.
  - Check application dependencies and target a framework version installed at:
      /usr/share/dotnet/shared/Microsoft.NETCore.App
  - The following versions are installed:
      1.1.0
  - Alternatively, install the framework version '1.0.0'.

When I look at what packages are installed locally (with 'dot' in their name) I find....

dpkg --get-selections | grep -v deinstall | grep dot

dotnet-dev-1.0.0-preview2-1-003177              install
dotnet-host                                     install
dotnet-hostfxr-1.1.0                            install
dotnet-sharedframework-microsoft.netcore.app-1.1.0      install

Whereas on my ancient (6 month old) linux machine I have:

dpkg --get-selections | grep -v deinstall | grep dot

dotnet-dev-1.0.0-preview2-003121                install
dotnet-host                                     install
dotnet-hostfxr-1.0.1                            install
dotnet-sharedframework-microsoft.netcore.app-1.0.0      install

(You can also use dotnet --version to see which dotnet is installed... but I like the approach above because it tells me more than I need. dotnet --info is also quite informative, as it should be.)

Looking into this some more, over at https://www.microsoft.com/net/download/linux it says this about the supported and current versions...

.NET Core 1.0.3 (LTS) (Long-Term-Support)
Ubuntu 16.04:  sudo apt-get install dotnet-dev-1.0.0-preview2-003156

And

.NET Core 1.1 (Current)
Ubuntu 16.04:  apt-get install dotnet-dev-1.0.0-preview2-003175

(Why is current not the same as what's on the front screen? And why doesn't the current need 'sudo'? (lodged it with jongalloway via twitter -- it got fixed 😊 )

Putting all these facts together:

6-months-ago    dotnet-dev-1.0.0-preview2-003121
"LTS"           dotnet-dev-1.0.0-preview2-003156
"current"       dotnet-dev-1.0.0-preview2-003175
Yesterday       dotnet-dev-1.0.0-preview2-1-003177

I think I want to install that older one, the LTS version (1.0.3)

So I run this:

sudo apt-get install dotnet-dev-1.0.0-preview2-003156

After that it seems to work okay.

On a "more recent" machine with (hopefully) .net core 2.2 I see:

$ dpkg --get-selections | grep -v deinstall | grep dot
dotnet-host                                     install
dotnet-hostfxr-2.2                              install
dotnet-runtime-2.2                              install
dotnet-runtime-deps-2.2                         install
dotnet-sdk-2.2                                  install

And on another seemingly with 2.1 I get....

$ dpkg --get-selections | grep -v deinstall | grep dot
dotnet-dev-1.0.0-preview2-003121                install
dotnet-host                                     install
dotnet-hostfxr-1.0.1                            install
dotnet-hostfxr-2.1                              install
dotnet-runtime-2.1                              install
dotnet-runtime-deps-2.1                         install
dotnet-sdk-2.1                                  install
dotnet-sharedframework-microsoft.netcore.app-1.0.0      install