internal/rosa: migrate GNU software

These are quite trivial, so migrate them in one pass.

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

internal/rosa/rosa.go

@@ -388,7 +388,7 @@ type Helper interface {
 	// also empty. The special value helperInPlace omits the cd statement.
 	wantsDir() string
 	// script returns the helper-specific segment of cure script.
-	script(s *S, name string) string
+	script(t Toolchain, name string) string
 }
 
 // PackageAttr holds build-system-agnostic attributes.
@@ -531,7 +531,7 @@ cd '/usr/src/` + name + `/'
 		extraRes,
 		attr.KnownChecksum,
 		attr.Env,
-		scriptEarly+helper.script(t.S, name),
+		scriptEarly+helper.script(t, name),
 		slices.Concat(attr.Paths, []pkg.ExecPath{
 			pkg.Path(AbsUsrSrc.Append(
 				name+sourceSuffix,
@@ -545,11 +545,11 @@ cd '/usr/src/` + name + `/'
 const (
 	// jobsE is expression for preferred job count set by [pkg].
 	jobsE = `"$` + pkg.EnvJobs + `"`
-	// jobsE is expression for flag with preferred job count.
+	// jobsFlagE is expression for flag with preferred job count.
 	jobsFlagE = `"-j$` + pkg.EnvJobs + `"`
 	// jobsLE is expression for twice of preferred job count set by [pkg].
 	jobsLE = `"$(expr ` + jobsE + ` '*' 2)"`
-	// jobsE is expression for flag with double of preferred job count.
+	// jobsLFlagE is expression for flag with double of preferred job count.
 	jobsLFlagE = `"-j$(expr ` + jobsE + ` '*' 2)"`
 )
 
@@ -624,7 +624,7 @@ func init() {
 		panic(err)
 	}
 	if err = native.EvaluateFS(sub); err != nil {
-		println(err)
+		println(err.Error())
 		os.Exit(1)
 	}
 }