feature/featuretags: make CLI connection error diagnostics modular

Updates #12614

Change-Id: I09b8944166ee00910b402bcd5725cd7969e2c82c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

feature/buildfeatures/feature_cliconndiag_disabled.go

@@ -0,0 +1,13 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Code generated by gen.go; DO NOT EDIT.
+
+//go:build ts_omit_cliconndiag
+
+package buildfeatures
+
+// HasCLIConnDiag is whether the binary was built with support for modular feature "CLI connection error diagnostics".
+// Specifically, it's whether the binary was NOT built with the "ts_omit_cliconndiag" build tag.
+// It's a const so it can be used for dead code elimination.
+const HasCLIConnDiag = false

feature/buildfeatures/feature_cliconndiag_enabled.go

@@ -0,0 +1,13 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Code generated by gen.go; DO NOT EDIT.
+
+//go:build !ts_omit_cliconndiag
+
+package buildfeatures
+
+// HasCLIConnDiag is whether the binary was built with support for modular feature "CLI connection error diagnostics".
+// Specifically, it's whether the binary was NOT built with the "ts_omit_cliconndiag" build tag.
+// It's a const so it can be used for dead code elimination.
+const HasCLIConnDiag = true

feature/featuretags/featuretags.go

@@ -96,6 +96,7 @@ var Features = map[FeatureTag]FeatureMeta{
 	"captiveportal": {"CaptivePortal", "Captive portal detection", nil},
 	"capture":       {"Capture", "Packet capture", nil},
 	"cli":           {"CLI", "embed the CLI into the tailscaled binary", nil},
+	"cliconndiag":   {"CLIConnDiag", "CLI connection error diagnostics", nil},
 	"completion":    {"Completion", "CLI shell completion", nil},
 	"dbus":          {"DBus", "Linux DBus support", nil},
 	"debugeventbus": {"DebugEventBus", "eventbus debug support", nil},