dashboard, app/appengine: set a known issue for staticlockranking builder

The linux-amd64-staticlockranking builder was added pre-emptively so
that it could be tested and used during the development of a CL that
implements a new feature. It's expected to fail until that work is
completed. Mark it as a builder with a known issue, golang/go#38029.

The new BuildConfig.KnownIssue field can be used by builders being
added in the future so that if they fail at first, it doesn't take
away time for people looking at build.golang.org, which we always
aim to have as green as possible¹.

¹ https://groups.google.com/d/msg/golang-dev/y0yM_Xi665Q/hUpBiUPiCAAJ

Fixes golang/go#38283
For golang/go#38029
For golang/go#37937
For golang/go#11811

Change-Id: Iba1606c7021ffa7e67ddbaae2fc6b65f4e46ab34
Reviewed-on: https://go-review.googlesource.com/c/build/+/227379
Reviewed-by: Alexander Rakoczy <[email protected]>

Author: dmitshur

app/appengine/build.go

@@ -306,6 +306,17 @@ func isUntested(builder, repo, branch, goBranch string) bool {
 	return !bc.BuildsRepoPostSubmit(repo, branch, goBranch)
 }
 
+// knownIssue returns a known issue for the named builder,
+// or zero if there isn't a known issue.
+func knownIssue(builder string) int {
+	bc, ok := dashboard.Builders[builder]
+	if !ok {
+		// Unknown builder.
+		return 0
+	}
+	return bc.KnownIssue
+}
+
 // Results returns the build Results for this Commit.
 func (c *CommitInfo) Results() (results []*Result) {
 	for _, r := range c.ResultData {

app/appengine/ui.go

@@ -818,6 +818,7 @@ var tmplFuncs = template.FuncMap{
 	"shortUser":          shortUser,
 	"unsupported":        unsupported,
 	"isUntested":         isUntested,
+	"knownIssue":         knownIssue,
 	"formatTime":         formatTime,
 }
 

app/appengine/ui.html

@@ -84,7 +84,7 @@ <h1>Go Dashboard</h1>
         <th></th>
         <th></th>
     {{range $.Builders}}
-        <th class="result arch{{if (unsupported .)}} unsupported{{end}}" title="{{.}}">{{builderSubheading .}}</th>
+        <th class="result arch{{if (unsupported .)}} unsupported{{end}}{{if knownIssue .}} noise{{end}}" title="{{.}}">{{builderSubheading .}}</th>
     {{end}}
       </tr>
 
@@ -94,7 +94,7 @@ <h1>Go Dashboard</h1>
         <th></th>
         <th></th>
     {{range $.Builders}}
-        <th class="result arch{{if (unsupported .)}} unsupported{{end}}" title="{{.}}">{{builderSubheading2 .}}</th>
+        <th class="result arch{{if (unsupported .)}} unsupported{{end}}{{if knownIssue .}} noise{{end}}" title="{{.}}">{{builderSubheading2 .}}</th>
     {{end}}
       </tr>
 
@@ -125,7 +125,9 @@ <h1>Go Dashboard</h1>
                 {{if .BuildingURL}}
                   <a href="{{.BuildingURL}}"><img src="https://golang.org/favicon.ico" height=16 width=16 border=0></a>
                 {{else if .OK}}
-                  <span class="ok">ok</span>
+                  <span class="ok{{if knownIssue $builderName}} noise{{end}}">ok</span>
+                {{else if knownIssue $builderName}}
+                  <a href="/log/{{.LogHash}}" class="noise" title="Builder {{$builderName}} has a known issue. See golang.org/issue/{{knownIssue $builderName}}.">fail</a>
                 {{else}}
                   <a href="/log/{{.LogHash}}" class="fail">fail</a>
                 {{end}}

dashboard/builders.go

@@ -685,7 +685,7 @@ func init() {
 }
 
 // A HostConfig describes the available ways to obtain buildlets of
-// different types. Some host configs can server multiple
+// different types. Some host configs can serve multiple
 // builders. For example, a host config of "host-linux-jessie" can
 // serve linux-amd64, linux-amd64-race, linux-386, linux-386-387, etc.
 type HostConfig struct {
@@ -748,6 +748,16 @@ type BuildConfig struct {
 	// For example, "host-linux-jessie".
 	HostType string
 
+	// KnownIssue is a non-zero golang.org/issue/nnn number for a builder
+	// that is known to be failing for some reason, such as because it is
+	// a new builder still in development/testing, or because the feature
+	// or port that it's meant to test hasn't been added yet, etc.
+	//
+	// A non-zero value here means that failures on this builder should not
+	// be considered a serious regression and don't need investigation beyond
+	// what is already in scope of the listed issue.
+	KnownIssue int
+
 	Notes string // notes for humans
 
 	// tryBot optionally specifies a policy func for whether trybots are enabled.
@@ -1599,9 +1609,10 @@ func init() {
 		},
 	})
 	addBuilder(BuildConfig{
-		Name:     "linux-amd64-staticlockranking",
-		HostType: "host-linux-stretch",
-		Notes:    "builder with GOEXPERIMENT=staticlockranking, see golang.org/issue/37937",
+		Name:       "linux-amd64-staticlockranking",
+		HostType:   "host-linux-stretch",
+		Notes:      "builder with GOEXPERIMENT=staticlockranking, see golang.org/issue/38029",
+		KnownIssue: 38029,
 		buildsRepo: func(repo, branch, goBranch string) bool {
 			return repo == "go" && atLeastGo1(goBranch, 15)
 		},