CI output: Spectre markup in log messages renders as literal text

[thomhurst]

Symptom

In GitHub Actions logs (e.g. run 25762828216, job 75668091053), many module completion lines look like:

[INFO ] [green]✓[/] Module [cyan]FindProjectsModule[/] completed successfully
[INFO ] [green]✓[/] Module [cyan]PrintEnvironmentVariablesModule[/] completed successfully
[INFO ] [green]✓[/] Module [cyan]NugetVersionGeneratorModule[/] completed successfully

The [green]✓[/] / [cyan]…[/] Spectre markup is being printed verbatim instead of rendered.

Cause

Producer code calls e.g.:

_logger.LogInformation("[green]✓[/] Module [cyan]{Name}[/] completed successfully", moduleName);

MEL.Spectre's message formatter (correctly, by default) treats the message template as literal text and escapes [ / ] so untrusted content can't break out into Spectre markup. The producer's embedded markup is therefore escaped rather than rendered.

Resolution

Once thomhurst/Spectre.MEL#2 lands and a new MEL.Spectre version is published, ModularPipelines can opt in:

services.AddLogging(b => b.AddSpectreConsole(o =>
{
    o.AllowMarkupInMessageTemplate = true;
}));

That makes [green]…[/] pass through to the renderer while still escaping placeholder values.

Alternative (preferred long-term)

Refactor to use semantic placeholders rather than literal markup tokens, e.g.:

_logger.LogInformation("{Status} Module {Name} completed", "✓", moduleName);

Then style via SpectreTheme.Placeholders.ForName("Status", new Style(Color.Green)) etc. Removes coupling between application code and a specific console renderer.