SEGFAULT sometimes occurs when testing libloading code

[binkoni]

Operating system is Fedora 27.

uname -r
4.15.4-300.fc27.x86_64

When running cargo test multiple times, sometimes test fails raising a segmentation fault.

#[test]
fn libloading() {
    let lib = libloading::Library::new("libdltest.so").unwrap();
    unsafe {
        let test_fn: libloading::Symbol<unsafe extern fn(i32) -> i32> = lib.get(b"test").unwrap();
        assert!(test_fn(100) == 200);
    }
}

test test::libloading ... error: process didn't exit successfully: `/home/User/test_libloading/target/debug/deps/test_libloading-b3311c80df7834fd libloading` (signal: 11, SIGSEGV: invalid memory reference)

But when this code runs in an executable crate, It seems to run without the segfault even when I execute it multiple times.

fn main() {
    let lib = libloading::Library::new("libdltest.so").unwrap();
    unsafe {
        let test_fn: libloading::Symbol<unsafe extern fn(i32) -> i32> = lib.get(b"test").unwrap();
        assert!(test_fn(100) == 200);
    }
}