progressui: constant prefix index for grep

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

util/progress/progressui/display.go

@@ -220,7 +220,7 @@ func (t *trace) update(s *client.SolveStatus) {
 				if v.Started != nil {
 					ts = l.Timestamp.Sub(*v.Started)
 				}
-				v.logs = append(v.logs, []byte(fmt.Sprintf("%s %s", fmt.Sprintf("%#.4g", ts.Seconds())[:5], dt)))
+				v.logs = append(v.logs, []byte(fmt.Sprintf("#%d %s %s", v.index, fmt.Sprintf("%#.4g", ts.Seconds())[:5], dt)))
 			}
 		})
 		v.logsPartial = !complete

util/progress/progressui/printer.go

@@ -31,17 +31,17 @@ func (p *textMux) printVtx(t *trace, dgst digest.Digest) {
 			}
 			old.logsOffset = 0
 			old.count = 0
-			fmt.Fprintf(p.w, "# ...\n")
+			fmt.Fprintf(p.w, "#%d ...\n", v.index)
 		}
 
-		fmt.Fprintf(p.w, "\n# %d %s\n", v.index, limitString(v.Name, 72))
+		fmt.Fprintf(p.w, "\n#%d %s\n", v.index, limitString(v.Name, 72))
 	}
 
 	if len(v.events) != 0 {
 		v.logsOffset = 0
 	}
 	for _, ev := range v.events {
-		fmt.Fprintf(p.w, "# %s\n", ev)
+		fmt.Fprintf(p.w, "#%d %s\n", v.index, ev)
 	}
 	v.events = v.events[:0]
 
@@ -67,7 +67,7 @@ func (p *textMux) printVtx(t *trace, dgst digest.Digest) {
 			if s.Completed != nil {
 				tm += " done"
 			}
-			fmt.Fprintf(p.w, "# %s%s%s\n", s.ID, bytes, tm)
+			fmt.Fprintf(p.w, "#%d %s%s%s\n", v.index, s.ID, bytes, tm)
 		}
 	}
 	v.statusUpdates = map[string]struct{}{}