ENOSYS

Constant ENOSYS 

Source
pub const ENOSYS: i32 = 38;
Expand description

This error code is special: arch syscall entry code will return -ENOSYS if users try to call a syscall that doesn’t exist. To keep failures of syscalls that really do exist distinguishable from failures due to attempts to use a nonexistent syscall, syscall implementations should refrain from returning -ENOSYS.

Invalid system call number