Improve logged stacktraces

loggers/cli/cli.go

@@ -9,6 +9,7 @@ import (
 	"github.com/mattn/go-colorable"
 	"io"
 	"os"
+	"strings"
 	"sync"
 	"time"
 )
@@ -65,12 +66,63 @@ func (h *Handler) HandleLog(e *log.Entry) error {
 		if name != "error" {
 			continue
 		}
+
 		if err, ok := e.Fields.Get("error").(error); ok {
 			// Attach the stacktrace if it is missing at this point, but don't point
 			// it specifically to this line since that is irrelevant.
-			err = errors.WithStackDepthIf(err, 1)
-			fmt.Fprintf(h.Writer, "\n%s\n%+v\n\n", boldred.Sprintf("Stacktrace:"), err)
+			err = errors.WithStackDepthIf(err, 4)
+			formatted := fmt.Sprintf("\n%s\n%+v\n\n", boldred.Sprintf("Stacktrace:"), err)
+
+			if !strings.Contains(formatted, "runtime.goexit") {
+				_, _ = fmt.Fprint(h.Writer, formatted)
+				break
+			}
+
+			// Inserts a new-line between sections of a stack.
+			// When wrapping errors, you get multiple separate stacks that start with their message,
+			// this allows us to separate them with a new-line and view them more easily.
+			//
+			// For example:
+			//
+			// Stacktrace:
+			// readlink test: no such file or directory
+			// failed to read symlink target for 'test'
+			// github.com/pterodactyl/wings/server/filesystem.(*Archive).addToArchive
+			//         github.com/pterodactyl/wings/server/filesystem/archive.go:166
+			// ... (Truncated the stack for easier reading)
+			// runtime.goexit
+			//         runtime/asm_amd64.s:1374
+			// **NEW LINE INSERTED HERE**
+			// backup: error while generating server backup
+			// github.com/pterodactyl/wings/server.(*Server).Backup
+			//         github.com/pterodactyl/wings/server/backup.go:84
+			// ... (Truncated the stack for easier reading)
+			// runtime.goexit
+			//         runtime/asm_amd64.s:1374
+			//
+			var b strings.Builder
+			var endOfStack bool
+			for _, s := range strings.Split(formatted, "\n") {
+				b.WriteString(s + "\n")
+
+				if s == "runtime.goexit" {
+					endOfStack = true
+					continue
+				}
+
+				if !endOfStack {
+					continue
+				}
+
+				b.WriteString("\n")
+				endOfStack = false
+			}
+
+			_, _ = fmt.Fprint(h.Writer, b.String())
 		}
+
+		// Only one key with the name "error" can be in the map.
+		break
 	}
 
 	return nil