ldd shows no linked library when build with cc_library

[Whu-MT]

• Hi, I'm new to bazel. And I'm trying to compile a library that link anothin prebuild library. Here is my project tree overview.

├── libhello
│   ├── BUILD
│   ├── include
│   │   └── hello.h
│   ├── lib
│   │   └── libhello.so
│   └── src
│       └── hello.c
├── libhello_again
│   ├── BUILD
│   └── hello_again.c
└── WORKSPACE

• libhello/lib/libhello.so is a simple library that print "hello", hello.c and libhello/BUILD code as follows. Compiled with gcc -shared -o libhello.so src/hello.c -Iinclude

#include <stdio.h>
#include "hello.h"

void say_hello()
{
    printf("hello\n");
}

# BUILD
package(
    default_visibility = ["//visibility:public"],
)
HELLO_HEADERS = glob([
    "include/*.h",
])

HELLO_LIBRARIES = [
    "lib/libhello.so",
]

cc_library(
    name = "libhello",
    srcs = HELLO_LIBRARIES,
    hdrs = HELLO_HEADERS,
    includes = ["include"]
)

• libhello_again is another library that use the function say_hello from libhello. libhello_again/hello_again.c and libhello_again/BUILD code as follows:

#include "hello.h"
#include <stdio.h>

void hello_again()
{
    say_hello();
    printf("hello again\n");
}

# BUILD
package(
    default_visibility = ["//visibility:public"],
)
cc_library(
    name = "hello_again",
    srcs = ["hello_again.c"],
    deps = [
        "//libhello:libhello",
    ],
)

• My question is: after build with bazel build //..., bazel-bin/libhello_again/libhello_again.so is compiled, but ldd bazel-bin/libhello_again/libhello_again.so shows no link to libhello.so, and nm shows that say_hello is a Undefined symbol.

➜  bazel_help ✗ ldd bazel-bin/libhello_again/libhello_again.so
        linux-vdso.so.1 (0x000076d8f7b82000)
        libc.so.6 => /usr/lib/libc.so.6 (0x000076d8f7946000)
        /usr/lib64/ld-linux-x86-64.so.2 (0x000076d8f7b84000)
➜  bazel_help ✗ nm bazel-bin/libhello_again/libhello_again.so | grep U
                 U puts
                 U say_hello

• Any suggestions would be very helpful, Thanks a lot.