dashboard: require at least Go 1.13 for illumos builder

Support for GOOS=illumos was added in CL 174457 which will be part of Go 1.13

Change-Id: I11c5b646c6f8147185526c58b6357d8a0e607187
Reviewed-on: https://go-review.googlesource.com/c/build/+/180157
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/dashboard/builders.go b/dashboard/builders.go
index 9fa15d4..6383113 100644
--- a/dashboard/builders.go
+++ b/dashboard/builders.go
@@ -2045,8 +2045,9 @@
 		HostType: "host-solaris-amd64",
 	})
 	addBuilder(BuildConfig{
-		Name:     "illumos-amd64-joyent",
-		HostType: "host-illumos-amd64-joyent",
+		Name:             "illumos-amd64-joyent",
+		HostType:         "host-illumos-amd64-joyent",
+		MinimumGoVersion: types.MajorMinor{1, 13},
 	})
 	addBuilder(BuildConfig{
 		Name:     "linux-ppc64-buildlet",
diff --git a/dashboard/builders_test.go b/dashboard/builders_test.go
index e3425e2..ed27c90 100644
--- a/dashboard/builders_test.go
+++ b/dashboard/builders_test.go
@@ -357,6 +357,16 @@
 		{b("aix-ppc64@go1.11", "go"), none},
 		{b("aix-ppc64@go1.11", "net"), none},
 
+		// Illumos starts at Go 1.13
+		{b("illumos-amd64-joyent", "go"), onlyPost},
+		{b("illumos-amd64-joyent", "net"), onlyPost},
+		{b("illumos-amd64-joyent", "sys"), onlyPost},
+		{b("illumos-amd64-joyent@1.13", "go"), onlyPost},
+		{b("illumos-amd64-joyent@1.12", "go"), none},
+		{b("illumos-amd64-joyent@1.12", "sys"), none},
+		{b("illumos-amd64-joyent@1.11", "go"), none},
+		{b("illumos-amd64-joyent@1.11", "sys"), none},
+
 		{b("linux-amd64-nocgo", "mobile"), none},
 
 		// Virtual mobiledevices