dashboard: add linux-arm64-longtest builder

For golang/go#49649.
Updates golang/go#53851.

Change-Id: Ifbfd2b089b909542d0568d529ba738e4b217cf5c
Reviewed-on: https://go-review.googlesource.com/c/build/+/452858
Reviewed-by: Dmitri Shuralyov <[email protected]>
Run-TryBot: Cherry Mui <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

Author: cherrymui

dashboard/builders.go

@@ -2604,6 +2604,30 @@ func init() {
 			return atLeastGo1(goBranch, 19) && buildRepoByDefault(repo)
 		},
 	})
+	addBuilder(BuildConfig{
+		Name:     "linux-arm64-longtest",
+		HostType: "host-linux-arm64-bullseye",
+		Notes:    "Debian Bullseye with go test -short=false",
+		// TODO: make it trybot on release branch once we know it works.
+		//tryBot: func(repo, branch, goBranch string) bool {
+		//	onReleaseBranch := strings.HasPrefix(branch, "release-branch.")
+		//	return repo == "go" && onReleaseBranch // See issue 37827.
+		//},
+		buildsRepo: func(repo, branch, goBranch string) bool {
+			b := buildRepoByDefault(repo)
+			if repo != "go" && !(branch == "master" && goBranch == "master") {
+				// For golang.org/x repos, don't test non-latest versions.
+				b = false
+			}
+			return b
+		},
+		needsGoProxy: true, // for cmd/go module tests
+		env: []string{
+			"GO_TEST_TIMEOUT_SCALE=5", // give them lots of time
+		},
+		numTryTestHelpers: 4, // Target time is < 15 min for go.dev/issue/42661.
+		KnownIssues:       []int{53851, 49649},
+	})
 	addBuilder(BuildConfig{
 		Name:              "linux-arm-aws",
 		HostType:          "host-linux-arm-aws",

dashboard/builders_test.go

@@ -159,6 +159,7 @@ func TestTrybots(t *testing.T) {
 				// Include longtest builders on Go repo release branches. See issue 37827.
 				"linux-386-longtest",
 				"linux-amd64-longtest",
+				//"linux-arm64-longtest",
 				"windows-amd64-longtest",
 			},
 		},
@@ -196,6 +197,7 @@ func TestTrybots(t *testing.T) {
 				// Include longtest builders on Go repo release branches. See issue 37827.
 				"linux-386-longtest",
 				"linux-amd64-longtest",
+				//"linux-arm64-longtest",
 				"windows-amd64-longtest",
 			},
 		},