include cleanups: remove unused headers and add feature test macros

[musl] / src / env / clearenv.c

diff --git a/src/env/clearenv.c b/src/env/clearenv.c
index a2475ce..62d5095 100644 (file)
--- a/src/env/clearenv.c
+++ b/src/env/clearenv.c
@@ -1,3 +1,4 @@
+#define _GNU_SOURCE
 #include <stdlib.h>
 
 extern char **__environ;