fmsg: implement suspend in writer

This removes the requirement to call fmsg.Exit on every exit path, and enables direct use of the "log" package. However, fmsg.BeforeExit is still encouraged when possible to catch exit on suspended output.

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

cmd/fpkg/start.go

@@ -2,11 +2,12 @@ package main
 
 import (
 	"flag"
+	"log"
 	"path"
 
 	"git.gensokyo.uk/security/fortify/fst"
 	"git.gensokyo.uk/security/fortify/helper/bwrap"
-	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal"
 )
 
 func actionStart(args []string) {
@@ -26,7 +27,7 @@ func actionStart(args []string) {
 	args = set.Args()
 
 	if len(args) < 1 {
-		fmsg.Fatal("invalid argument")
+		log.Fatal("invalid argument")
 	}
 
 	/*
@@ -37,7 +38,7 @@ func actionStart(args []string) {
 	pathSet := pathSetByApp(id)
 	app := loadBundleInfo(pathSet.metaPath, func() {})
 	if app.ID != id {
-		fmsg.Fatalf("app %q claims to have identifier %q", id, app.ID)
+		log.Fatalf("app %q claims to have identifier %q", id, app.ID)
 	}
 
 	/*
@@ -144,7 +145,7 @@ func actionStart(args []string) {
 	*/
 
 	fortifyApp(config, func() {})
-	fmsg.Exit(0)
+	internal.Exit(0)
 }
 
 func appendGPUFilesystem(config *fst.Config) {