runtime: handle GODEBUG on wasip2

Author: jakebailey

src/runtime/env.go

@@ -1,4 +1,4 @@
-//go:build linux || darwin || windows || wasip1
+//go:build (linux || darwin || windows || wasip1) && !wasip2
 
 package runtime
 

src/runtime/env_wasip2.go

@@ -0,0 +1,18 @@
+//go:build wasip2
+
+package runtime
+
+// Notify the runtime when environment variables change.
+// On wasip2, the environment is managed in Go (no C setenv), but
+// internal/godebug still needs to be notified of GODEBUG changes.
+
+//go:linkname syscallSetenv syscall.runtimeSetenv
+func syscallSetenv(key, value string) {
+	if key == "GODEBUG" && godebugUpdate != nil {
+		godebugUpdate(key, value)
+	}
+}
+
+//go:linkname syscallUnsetenv syscall.runtimeUnsetenv
+func syscallUnsetenv(key string) {
+}

src/syscall/env_wasip2.go

@@ -43,11 +43,13 @@ func Setenv(key, val string) (err error) {
 		}
 	}
 	libc_envs[key] = val
+	runtimeSetenv(key, val)
 	return nil
 }
 
 func Unsetenv(key string) (err error) {
 	delete(libc_envs, key)
+	runtimeUnsetenv(key)
 	return nil
 }