Compact diagnostics for mutants that ended as :harness_error.
The runner already captures the raw mix test output, but the final reports
need a short, stable summary rather than an entire suite log. This module is the
shared presentation layer for human, JSON, live, and abort messages.
It only formats. Picking the output line to show and recognising the known boot
crash both read mix's output format, which Mutare.Sandbox.Command.Output owns
(salient_line/1, boot_failure?/1).
Summary
Functions
Return a site-prefixed diagnostic line suitable for multi-error summaries.
Return a one-line diagnostic for a harness-errored result.
Functions
@spec line(Mutare.Result.t()) :: String.t()
Return a site-prefixed diagnostic line suitable for multi-error summaries.
@spec summary(Mutare.Result.t()) :: String.t()
Return a one-line diagnostic for a harness-errored result.
Includes the exit status when known plus the output's salient line
(Mutare.Sandbox.Command.Output.salient_line/1), truncated. The known
self-erasing boot crash gets a cause-specific summary because its output is
explicitly not useful for recovering the original exception.