fix: don't fail the whole SBOM when a cataloger panics on one file (#5342)

* fix(generic): recover from parser and processor panics

- a panic while parsing one file becomes an unknown for that location instead of failing the whole SBOM
- a panic in a package processor is logged as a warning and the unprocessed results are kept
- stacks go to the trace log, not into the unknown text

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* fix(unknown): keep errors that unwrap to nil

`sync.PanicError` with a non-error panic value (e.g. `panic("boom")`) unwraps to nil, and was being dropped entirely from the error graph instead of being kept as a leaf.

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* fix(task): don't put the stack trace in task panic errors

Task panics are still fatal, but the error now reads `panic in task "<name>": <value>` and the stack goes to the debug log.

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* test(generic): cover chained processors when a later one panics

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* fix(file): recover from panics in the executable and file digest catalogers

A panic while reading one file is now recorded as an unknown for that file instead of failing the whole SBOM, the same as generic catalogers.

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

---------

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

internal/task/executor_test.go

@@ -8,8 +8,12 @@ import (
 	"github.com/wagoodman/go-progress"
 
 	"github.com/anchore/syft/internal/sbomsync"
+	"github.com/anchore/syft/syft/artifact"
 	"github.com/anchore/syft/syft/event/monitor"
 	"github.com/anchore/syft/syft/file"
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/anchore/syft/syft/pkg/cataloger/generic"
+	"github.com/anchore/syft/syft/sbom"
 )
 
 func Test_TaskExecutor_PanicHandling(t *testing.T) {
@@ -21,6 +25,20 @@ func Test_TaskExecutor_PanicHandling(t *testing.T) {
 		Manual: progress.NewManual(-1),
 	})
 
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "executor_test.go")
+	require.EqualError(t, err, `panic in task "panicking-cataloger": something bad happened`)
+}
+
+func Test_RunTask_GenericParserPanicBecomesUnknown(t *testing.T) {
+	c := generic.NewCataloger("panicking-cataloger").
+		WithParserByPath(func(context.Context, file.Resolver, *generic.Environment, file.LocationReadCloser) ([]pkg.Package, []artifact.Relationship, error) {
+			panic("boom")
+		}, "executor_test.go")
+	s := &sbom.SBOM{}
+
+	err := RunTask(context.Background(), NewPackageTask(DefaultCatalogingFactoryConfig(), c), file.NewMockResolverForPaths("executor_test.go"), sbomsync.NewBuilder(s), &monitor.TaskProgress{
+		Manual: progress.NewManual(-1),
+	})
+
+	require.NoError(t, err)
+	require.Len(t, s.Artifacts.Unknowns, 1)
 }