Function build 

fn build(
    root: &Path,
    target_os: &str,
    cc: &str,
    ar: &str,
    extra_cflags: &[&str],
) -> Result<()>

Compiles mupdf_wrapper.c into libmupdf_wrapper.a.

Equivalent to the shell commands:

$CC -I../thirdparty/mupdf/include -c mupdf_wrapper.c -o $BUILD_DIR/mupdf_wrapper.o
$AR -rcs $BUILD_DIR/libmupdf_wrapper.a $BUILD_DIR/mupdf_wrapper.o

Errors

Returns an error if the compiler or archiver invocation fails.