internal/pkg: optionally suppress init verbosity

This flag applies to every exec artifact cured by the cache. It has no effect on cure outcome.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pkg/exec.go

@@ -436,6 +436,7 @@ func (a *execArtifact) makeContainer(
 	if z.HostNet {
 		z.Hostname = "cure-net"
 	}
+	z.Quiet = flags&CSuppressInit != 0
 	z.Uid, z.Gid = (1<<10)-1, (1<<10)-1
 	z.Dir, z.Path, z.Args = a.dir, a.path, a.args
 	z.Env = slices.Concat(a.env, []string{EnvJobs + "=" + strconv.Itoa(jobs)})

internal/pkg/pkg.go

@@ -617,6 +617,10 @@ const (
 	// CPromoteVariant allows [pkg.Open] to promote an unextended on-disk cache
 	// to the current extension variant. This is a one-way operation.
 	CPromoteVariant
+
+	// CSuppressInit arranges for verbose output of the container init to be
+	// suppressed regardless of [message.Msg] state.
+	CSuppressInit
 )
 
 // toplevel holds [context.WithCancel] over caller-supplied context, where all