Routing of AssertError messages

[jfondren]

On Saturday, 31 July 2021 at 12:03:49 UTC, DLearner wrote:
> Hi
>
> This may be due to Windows, not DMD.
>
> Please see code below (held in test.d):
>
> ```
> void main() {
>    import std.stdio;
>
>    writeln("Test");
>    assert(false, "TestAssert");
> }
> ```
> `
> dmd -i -run test.d
> `
> results in both "Test" and the "TestAssert" string (and trace) 
> being routed to screen.
>
> But
> `
> dmd -i -run test.d > op.txt
> `
> results in only "Test" going into op.txt, the "TestAssert" 
> string (and trace) being routed to screen as before.
>
> I expected both "Test" and the "TestAssert" string (and trace) 
> to go into op.txt.

"Test" is written to the standard out stream; "TestAssert" is 
written to the standard error stream. > only redirects standard 
out, so the error stream continues to write to the terminal.

Stream redirection depends on your shell. PowerShell docs appear 
to be here:
https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_redirection?view=powershell-7.1