I am making a C++ SDL based game engine, currently installing SDL mixer X, because it supports more formats. It asked several dependencies which I installed but then after compiling the .so file doesn't show them, why is this?

$ make -j 4
[  2%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_cmd.c.o
[ 10%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/load_aiff.c.o
[ 10%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/load_voc.c.o
[ 10%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/mp3utils.c.o
[ 12%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_drflac.c.o
[ 15%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_flac.c.o
[ 17%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_fluidsynth.c.o
[ 20%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_gme.c.o
[ 23%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_minimp3.c.o
[ 25%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_modplug.c.o
[ 28%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_mpg123.c.o
[ 30%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_nativemidi.c.o
[ 33%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_ogg.c.o
[ 35%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_ogg_stb.c.o
[ 38%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_opus.c.o
[ 41%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_timidity.c.o
[ 43%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_wav.c.o
[ 46%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_wavpack.c.o
[ 48%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/music_xmp.c.o
[ 51%] Building C object CMakeFiles/SDL2_mixer.dir/src/effect_position.c.o
[ 53%] Building C object CMakeFiles/SDL2_mixer.dir/src/effect_stereoreverse.c.o
[ 56%] Building C object CMakeFiles/SDL2_mixer.dir/src/effects_internal.c.o
[ 58%] Building C object CMakeFiles/SDL2_mixer.dir/src/mixer.c.o
[ 61%] Building C object CMakeFiles/SDL2_mixer.dir/src/music.c.o
[ 64%] Building C object CMakeFiles/SDL2_mixer.dir/src/utils.c.o
[ 66%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/timidity/common.c.o
[ 69%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/timidity/instrum.c.o
[ 71%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/timidity/mix.c.o
[ 74%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/timidity/output.c.o
[ 76%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/timidity/playmidi.c.o
[ 79%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/timidity/readmidi.c.o
[ 82%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/timidity/resample.c.o
[ 84%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/timidity/tables.c.o
[ 87%] Building C object CMakeFiles/SDL2_mixer.dir/src/codecs/timidity/timidity.c.o
[ 89%] Linking C shared library libSDL2_mixer-2.0.so
[ 89%] Built target SDL2_mixer
[ 92%] Building C object CMakeFiles/playmus.dir/playmus.c.o
[ 94%] Building C object CMakeFiles/playwave.dir/playwave.c.o
[ 97%] Linking C executable playwave
[100%] Linking C executable playmus
[100%] Built target playwave
[100%] Built target playmus

$ ldd libSDL2_mixer.so
	linux-vdso.so.1 (0x00007fffe075a000)
	libSDL2-2.0.so.0 => /lib64/libSDL2-2.0.so.0 (0x00007f7b007e6000)
	libc.so.6 => /lib64/libc.so.6 (0x00007f7b00400000)
	libasound.so.2 => /lib64/libasound.so.2 (0x00007f7b006dc000)
	libm.so.6 => /lib64/libm.so.6 (0x00007f7b00319000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f7b00a53000)