```dotnet run``` with invalid launch profile name does not populate ```DOTNET_LAUNCH_PROFILE``` with actual profile selected.

[mitchdenny]

Describe the bug

I just recently added support for populating an environment variable (DOTNET_LAUNCH_PROFILE) when a developer uses dotnet run or dotnet watch. I was testing this feature out with the nightly build and found an inconsistency between dotnet watch and dotnet run. If I specify a launch profile on the command-line that does not exist in dotnet watch it will populate the variable with the launch profile that is actually selected (by default the first in the list). Unfortunately I didn't implement the same behavior with dotnet run so the variable isn't populated.

Capturing the problem in this issue and self-assigning to get in before RC2.

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[mitchdenny]

Actually, this down to a difference between dotnet run and dotnet watch. When dotnet run is launched with a non-existent profile it doesn't use one, whereas dotnet watch uses the default. So the DOTNET_LAUNCH_PROFILE behavior is technically correct based on what dotnet run is doing.

Bit of a strange inconsistency between dotnet run and dotnet watch though.

Any thoughts @DamianEdwards?

[DamianEdwards]

Looks like something we should look to align behavior on in 9, probably brining dotnet watch inline with the dotnet run behavior.

[mitchdenny]

Unassigning and bucketing for 9.0