All printed warnings should have some context

cmd/syncthing/gui.go

@@ -278,7 +278,7 @@ func restPostConfig(m *model.Model, w http.ResponseWriter, r *http.Request) {
 	var newCfg config.Configuration
 	err := json.NewDecoder(r.Body).Decode(&newCfg)
 	if err != nil {
-		l.Warnln(err)
+		l.Warnln("decoding posted config:", err)
 		http.Error(w, err.Error(), 500)
 		return
 	} else {
@@ -289,7 +289,7 @@ func restPostConfig(m *model.Model, w http.ResponseWriter, r *http.Request) {
 		} else {
 			hash, err := bcrypt.GenerateFromPassword([]byte(newCfg.GUI.Password), 0)
 			if err != nil {
-				l.Warnln(err)
+				l.Warnln("bcrypting password:", err)
 				http.Error(w, err.Error(), 500)
 				return
 			} else {
@@ -513,7 +513,7 @@ func restGetLang(w http.ResponseWriter, r *http.Request) {
 func restPostUpgrade(w http.ResponseWriter, r *http.Request) {
 	rel, err := upgrade.LatestRelease(strings.Contains(Version, "-beta"))
 	if err != nil {
-		l.Warnln(err)
+		l.Warnln("getting latest release:", err)
 		http.Error(w, err.Error(), 500)
 		return
 	}
@@ -521,7 +521,7 @@ func restPostUpgrade(w http.ResponseWriter, r *http.Request) {
 	if upgrade.CompareVersions(rel.Tag, Version) == 1 {
 		err = upgrade.UpgradeTo(rel, GoArchExtra)
 		if err != nil {
-			l.Warnln(err)
+			l.Warnln("upgrading:", err)
 			http.Error(w, err.Error(), 500)
 			return
 		}

cmd/syncthing/gui_solaris.go

@@ -79,7 +79,7 @@ func trackCPUUsage() {
 	for _ = range time.NewTicker(time.Second).C {
 		err := solarisPrusage(pid, &rusage)
 		if err != nil {
-			l.Warnln(err)
+			l.Warnln("getting prusage:", err)
 			continue
 		}
 		curTime := time.Now().UnixNano()

config/config.go

@@ -315,7 +315,7 @@ func Load(rd io.Reader, myID protocol.NodeID) (Configuration, error) {
 	if len(cfg.GUI.Password) > 0 && cfg.GUI.Password[0] != '$' {
 		hash, err := bcrypt.GenerateFromPassword([]byte(cfg.GUI.Password), 0)
 		if err != nil {
-			l.Warnln(err)
+			l.Warnln("bcrypting password:", err)
 		} else {
 			cfg.GUI.Password = string(hash)
 		}

versioner/simple.go

@@ -96,7 +96,7 @@ func (v Simple) Archive(filePath string) error {
 
 	versions, err := filepath.Glob(filepath.Join(dir, file+"~*"))
 	if err != nil {
-		l.Warnln(err)
+		l.Warnln("globbing:", err)
 		return nil
 	}
 
@@ -108,7 +108,7 @@ func (v Simple) Archive(filePath string) error {
 			}
 			err = os.Remove(toRemove)
 			if err != nil {
-				l.Warnln(err)
+				l.Warnln("removing old version:", err)
 			}
 		}
 	}