I'm trying to compile an example program that links to the shared library produced by [Sundown](https://github.com/tanoku/sundown). I'm compiling the program like so.

```
$ gcc -o sd sundown.c -L. -lsundown

```

Yet, when I run it I get the following error.

> 
> ./sd: error while loading shared libraries: libsundown.so: cannot open shared object
>  file: No such file or directory
> 
> 
> 

The output of `ls` is.

```
$ ls
libsundown.so  libsundown.so.1  sundown.c  sd

```

Why is the shared library not found by `ld`?