main: Use latest Go 1.25 features if possible.

debug.go

@@ -0,0 +1,25 @@
+// Copyright (c) 2025 The Decred developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+// This file changes the default GODEBUG values when building with newer
+// releases of Go to enable as many of the new features and security updates
+// that are not strictly backwards compatible as possible.
+//
+// For reference, in order to avoid breaking backwards compatibility, newer
+// versions of Go toolchains automatically set GODEBUG flags to disable any
+// changes that are not strictly backwards compatible when compiling old code.
+// However, it is often the case that older code will work properly with the
+// new features and security updates enabled and those updates are generally
+// desirable.
+//
+// WARNING: Do not blindly update this with each new Go release.  It needs to
+// be analyzed with each new release before updating to ensure none of the
+// changes in the newer versions of Go that are disabled by default due to not
+// being strictly backwards compatible will break the existing code.
+
+//go:build go1.25
+
+//go:debug default=go1.25
+
+package main