add comment to know why it's weak

libc/misc/internals/__uClibc_main.c

@@ -98,6 +98,7 @@ strong_alias (__progname_full, program_invocation_name)
 libc_hidden_proto(__environ)
 char **__environ = 0;
 libc_hidden_def(__environ)
+/* psm: arm segfaults with strong_alias, although defined */
 weak_alias(__environ,environ)
 
 /* TODO: don't export __pagesize; we cant now because libpthread uses it */