@spec atom_exhausted?(String.t()) :: boolean()

Returns whether output shows the BEAM aborting because the atom table filled.

This is the signature of a mutation that mints unbounded atoms. The runner treats that as a kill, like a timeout, because the suite cannot complete with the mutation active.

This predicate only refines an otherwise-:harness_error exit in Mutare.Sandbox.Command.outcome/2; normal pass, fail, and timeout verdicts take precedence.

@spec boot_failure?(String.t()) :: boolean()

Returns whether output matches the known boot-failure harness error.

The signature is the emulator's terminating during boot message paired with a secondary :standard_error failure. The original diagnostic is usually gone by then, and the common cause is resource or connection contention while concurrent workers start.

The runner still records this as :harness_error, but it can show a more useful message and use the dedicated boot-failure retry budget. This predicate only refines an otherwise-:harness_error exit; normal pass, fail, and timeout verdicts take precedence.

@spec compile_error_banner() :: Regex.t()

Regex for Mix's == Compilation error in file <path> == banner.

The regex captures <path> and is used by suite_compile_error?/1.

@spec dependency_issue(String.t()) :: dependency_issue() | nil

Classify a dependency-check failure in captured Mix output.

Returns nil for output unrelated to dependencies. The categories deliberately follow Mix's own recommendations:

• :fetch — the lock/source state requires mix deps.get;
• :compile — sources exist but require mix deps.compile;
• :diverged — dependency declarations conflict;
• :unavailable — a non-fetchable dependency (normally a local/path dep) is missing from the sandbox's view of the filesystem;
• :invalid — another status under Mix's unchecked-dependencies banner.

The broad banner proves this is dependency validation, while the narrower recommendation phrases choose remediation. This keeps an arbitrary compiler error that merely mentions mix deps.get from being reclassified.

@spec diagnostic_severity(String.t()) :: :error | :warning | nil

Returns the diagnostic block started by a compiler-output line.

The result is :error for an error: header or raised ** (…Error), :warning for a warning: header, and nil for any other line. Body, footer, and chatter lines inherit the previous header's severity in the caller.

Mutare.Poison uses this to scan only non-warning lines for mutant locations. A failed metamutant compile can include warnings caused by mutations, and those warnings carry the same file:line footer shape as real errors. Separating the diagnostic blocks keeps warning locations from being treated as poison.

@spec output_tail(String.t(), pos_integer()) :: String.t()

Return the last lines lines of captured Mix output.

Used by baseline, coverage-probe, and Mix-task errors to show enough context without printing an entire suite run.

@spec source_location_regex() :: Regex.t()

Regex for a <file>:<line> source reference in Mix output.

It matches .ex and .exs paths such as lib/foo.ex:5 or test/foo_test.exs:42, capturing the file and line. Mutare.Poison uses it to map compile errors back to mutant ids.

@spec suite_compile_error?(String.t()) :: boolean()

Returns whether output reports a Mix compilation error in a test script.

This identifies a mutation that broke test-suite compilation. It matches the compile_error_banner/0 only when the captured path is a .exs file under a test/ directory. Lib-file errors and output without the banner return false.

@spec test_location_regex() :: Regex.t()

Regex for a <test_file>:<line> reference in Mix output.

This narrows source_location_regex/0 to _test.exs files. The baseline runner uses it to name tests involved in a flaky run.