Missing library while loading shared libraries: libisl so. 15: cannot open shared object file: No such file

rk3568 Cross compiler path ：

[email protected]100ask:~/prebuilts/gcc/linux-x86/aarch64/gcc-buildroot-9.3.0-2020.03-x86_64_aarch64-rockchip-linux-gnu/bin$ ls
2to3                             aarch64-linux-gcc-ar       aarch64-linux-strip                           aarch64-rockchip-linux-gnu-gcc.br_real  aclocal           gawk                    infocmp         msggrep          python2                  qemu-nbd
2to3-3.7                         aarch64-linux-gcc.br_real  aarch64-rockchip-linux-gnu-addr2line          aarch64-rockchip-linux-gnu-gcc-nm       aclocal-1.15      gdbus                   infotocap       msginit          python2.7                recode-sr-latin
aarch64-linux-addr2line          aarch64-linux-gcc-nm       aarch64-rockchip-linux-gnu-ar                 aarch64-rockchip-linux-gnu-gcc-ranlib   autoconf          gdbus-codegen           ivshmem-client  msgmerge         python2.7-config         reset
aarch64-linux-ar                 aarch64-linux-gcc-ranlib   aarch64-rockchip-linux-gnu-as                 aarch64-rockchip-linux-gnu-gcov         autoheader        gettextize              ivshmem-server  msgunfmt         python2-config           smtpd.py
aarch64-linux-as                 aarch64-linux-gcov         aarch64-rockchip-linux-gnu-c++                aarch64-rockchip-linux-gnu-gcov-dump    autom4te          gio                     libtool         msguniq          python3                  smtpd.py.7
aarch64-linux-c++                aarch64-linux-gcov-dump    aarch64-rockchip-linux-gnu-c++.br_real        aarch64-rockchip-linux-gnu-gcov-tool    automake          gio-querymodules        libtoolize      ncurses6-config  python3.7                tabs
aarch64-linux-c++.br_real        aarch64-linux-gcov-tool    aarch64-rockchip-linux-gnu-cc                 aarch64-rockchip-linux-gnu-gdb          automake-1.15     glib-compile-resources  lzip            ninja            python3.7-config         tic
aarch64-linux-cc                 aarch64-linux-gdb          aarch64-rockchip-linux-gnu-cc.br_real         aarch64-rockchip-linux-gnu-gprof        autopoint         glib-compile-schemas    m4              openssl          python3.7m               toe
aarch64-linux-cc.br_real         aarch64-linux-gprof        aarch64-rockchip-linux-gnu-c++filt            aarch64-rockchip-linux-gnu-ld           autoreconf        glib-genmarshal         meson           patchelf         python3.7m-config        toolchain-wrapper
aarch64-linux-c++filt            aarch64-linux-ld           aarch64-rockchip-linux-gnu-cpp                aarch64-rockchip-linux-gnu-ld.bfd       autoscan          glib-gettextize         msgattrib       pcre-config      python3-config           tput
aarch64-linux-cpp                aarch64-linux-ld.bfd       aarch64-rockchip-linux-gnu-cpp.br_real        aarch64-rockchip-linux-gnu-nm           autoupdate        glib-mkenums            msgcat          pcregrep         python-config            tset
aarch64-linux-cpp.br_real        aarch64-linux-nm           aarch64-rockchip-linux-gnu-elfedit            aarch64-rockchip-linux-gnu-objcopy      bison             gobject-query           msgcmp          pcretest         python-freeze-importlib  xgettext
aarch64-linux-elfedit            aarch64-linux-objcopy      aarch64-rockchip-linux-gnu-g++                aarch64-rockchip-linux-gnu-objdump      captoinfo         gresource               msgcomm         pkgconf          pyvenv                   xml2-config
aarch64-linux-g++                aarch64-linux-objdump      aarch64-rockchip-linux-gnu-g++.br_real        aarch64-rockchip-linux-gnu-ranlib       clear             gsettings               msgconv         pkg-config       qemu-aarch64             xmlcatalog
aarch64-linux-g++.br_real        aarch64-linux-ranlib       aarch64-rockchip-linux-gnu-gcc                aarch64-rockchip-linux-gnu-readelf      c_rehash          gtester                 msgen           pydoc            qemu-edid                xmllint
aarch64-linux-gcc                aarch64-linux-readelf      aarch64-rockchip-linux-gnu-gcc-9.3.0          aarch64-rockchip-linux-gnu-size         easy_install      gtester-report          msgexec         pydoc3           qemu-ga                  xmlwf
aarch64-linux-gcc-9.3.0          aarch64-linux-size         aarch64-rockchip-linux-gnu-gcc-9.3.0.br_real  aarch64-rockchip-linux-gnu-strings      easy_install-3.7  ifnames                 msgfilter       pydoc3.7         qemu-img                 yacc
aarch64-linux-gcc-9.3.0.br_real  aarch64-linux-strings      aarch64-rockchip-linux-gnu-gcc-ar             aarch64-rockchip-linux-gnu-strip        gapplication      igawk                   msgfmt          python           qemu-io

Configure environment variables ：

export PATH=$PATH:/home/book/prebuilts/gcc/linux-x86/aarch64/gcc-buildroot-9.3.0-2020.03-x86_64_aarch64-rockchip-linux-gnu/bin

Missing library path at compile time ：

aarch64-linux-gcc-9.3.0 -o tcp_ser tcp_server.c tcp_socket.c  tcp_socket.h 
/home/book/prebuilts/gcc/linux-x86/aarch64/gcc-buildroot-9.3.0-2020.03-x86_64_aarch64-rockchip-linux-gnu/bin/../libexec/gcc/aarch64-rockchip-linux-gnu/9.3.0/cc1: error while loading shared libraries: libisl.so.15: cannot open shared object file: No such file or directory
/home/book/prebuilts/gcc/linux-x86/aarch64/gcc-buildroot-9.3.0-2020.03-x86_64_aarch64-rockchip-linux-gnu/bin/../libexec/gcc/aarch64-rockchip-linux-gnu/9.3.0/cc1: error while loading shared libraries: libisl.so.15: cannot open shared object file: No such file or directory
/home/book/prebuilts/gcc/linux-x86/aarch64/gcc-buildroot-9.3.0-2020.03-x86_64_aarch64-rockchip-linux-gnu/bin/../libexec/gcc/aarch64-rockchip-linux-gnu/9.3.0/cc1: error while loading shared libraries: libisl.so.15: cannot open shared object file: No such file or directory

Find the missing dynamic library path , The path of the library to be used for the executable , When the environment variable is introduced, the operating system will look for the class library under the variable ：

export LD_LIBRARY_PATH=/usr/local/X11/lib:$LD_LIBRARY_PATH/home/book/prebuilts/gcc/linux-x86/aarch64/gcc-buildroot-9.3.0-2020.03-x86_64_aarch64-rockchip-linux-gnu/lib