In Powershell env vars are set via
```powershell
> $Env:DEFMT_LOG = "trace"
```
Trying to run the example, as formatted prior to this change:
```powershell
> Env: DEFMT_LOG = "trace"
Env: : The term 'Env:' is not recognized as the name of a cmdlet, function, script file, or operable program.
Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:1
+ Env: DEFMT_LOG = "trace"
+ ~~~~
+ CategoryInfo : ObjectNotFound: (Env::String) [], CommandNotFoundException
+ FullyQualifiedErrorId : CommandNotFoundException
```
This is documented in https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_environment_variables?view=powershell-7.2.