courier-authlib configure error

checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /usr/bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking for gawk... (cached) gawk
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking whether gcc understands -c and -o together... yes
checking whether make supports the include directive... yes (GNU style)
checking dependency style of gcc... gcc3
checking for gcc option to accept ISO C99... none needed
checking for g++... g++
checking whether we are using the GNU C++ compiler... yes
checking whether g++ accepts -g... yes
checking dependency style of g++... gcc3
checking how to run the C preprocessor... gcc -E
checking whether ln -s works... yes
checking for perl5... no
checking for perl... /usr/bin/perl
checking for sysconftool...... ././sysconftool
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking how to print strings... printf
checking for a sed that does not truncate output... /usr/bin/sed
checking for grep that handles long lines and -e... /usr/bin/grep
checking for egrep... /usr/bin/grep -E
checking for fgrep... /usr/bin/grep -F
checking for ld used by gcc... /usr/bin/ld
checking if the linker (/usr/bin/ld) is GNU ld... yes
checking for BSD- or MS-compatible name lister (nm)... /usr/bin/nm -B
checking the name lister (/usr/bin/nm -B) interface... BSD nm
checking the maximum length of command line arguments... 1572864
checking how to convert x86_64-pc-linux-gnu file names to x86_64-pc-linux-gnu format... func_convert_file_noop
checking how to convert x86_64-pc-linux-gnu file names to toolchain format... func_convert_file_noop
checking for /usr/bin/ld option to reload object files... -r
checking for objdump... objdump
checking how to recognize dependent libraries... pass_all
checking for dlltool... no
checking how to associate runtime and link libraries... printf %s\n
checking for ar... ar
checking for archiver @FILE support... @
checking for strip... strip
checking for ranlib... ranlib
checking command to parse /usr/bin/nm -B output from gcc object... ok
checking for sysroot... no
checking for a working dd... /usr/bin/dd
checking how to truncate binary pipes... /usr/bin/dd bs=4096 count=1
checking for mt... no
checking if : is a manifest tool... no
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking for dlfcn.h... yes
checking for objdir... .libs
checking if gcc supports -fno-rtti -fno-exceptions... no
checking for gcc option to produce PIC... -fPIC -DPIC
checking if gcc PIC flag -fPIC -DPIC works... yes
checking if gcc static flag -static works... yes
checking if gcc supports -c -o file.o... yes
checking if gcc supports -c -o file.o... (cached) yes
checking whether the gcc linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes
checking whether -lc should be explicitly linked in... no
checking dynamic linker characteristics... GNU/Linux ld.so
checking how to hardcode library paths into programs... immediate
checking for shl_load... no
checking for shl_load in -ldld... no
checking for dlopen... yes
checking whether a program can dlopen itself... yes
checking whether a statically linked program can dlopen itself... no
checking whether stripping libraries is possible... yes
checking if libtool supports shared libraries... yes
checking whether to build shared libraries... yes
checking whether to build static libraries... yes
checking how to run the C++ preprocessor... g++ -E
checking for ld used by g++... /usr/bin/ld -m elf_x86_64
checking if the linker (/usr/bin/ld -m elf_x86_64) is GNU ld... yes
checking whether the g++ linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes
checking for g++ option to produce PIC... -fPIC -DPIC
checking if g++ PIC flag -fPIC -DPIC works... yes
checking if g++ static flag -static works... yes
checking if g++ supports -c -o file.o... yes
checking if g++ supports -c -o file.o... (cached) yes
checking whether the g++ linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes
checking dynamic linker characteristics... (cached) GNU/Linux ld.so
checking how to hardcode library paths into programs... immediate
checking what extension is used for runtime loadable modules... .so
checking what variable specifies run-time module search path... LD_LIBRARY_PATH
checking for the default library search path... /lib64 /usr/lib64 /lib /usr/lib /usr/lib/R/lib /usr/lib/courier-authlib /opt/cuda/lib64 /opt/cuda/nvvm/lib64 /opt/cuda/extras/CUPTI/lib64 /usr/lib/libfakeroot /opt/intel/mkl/lib/intel64 /opt/intel/mkl/lib/i /opt/rocm-5.0.0/opencl/lib /opt/rocm-5.0.0/lib /usr/lib/opencollada /usr/lib/openmpi /usr/lib/perf /opt/picoscope/lib
checking for library containing dlopen... no
checking for dlopen in -lsvld... no
checking for shl_load... (cached) no
checking for shl_load in -ldld... (cached) no
checking for dld_link in -ldld... no
checking for _ prefix in compiled symbols... no
checking whether deplibs are loaded by dlopen... yes
checking for argz.h... no
checking for error_t... no
checking for argz_add... no
checking for argz_append... no
checking for argz_count... no
checking for argz_create_sep... no
checking for argz_insert... no
checking for argz_next... no
checking for argz_stringify... no
checking whether libtool supports -dlopen/-dlpreopen... yes
checking for ltdl.h... no
checking where to find libltdl headers... -I$(top_srcdir)/libltdl
checking where to find libltdl library... $(top_build_prefix)libltdl/libltdlc.la
checking for unistd.h... (cached) yes
checking for dl.h... no
checking for sys/dl.h... no
checking for dld.h... no
checking for mach-o/dyld.h... no
checking for dirent.h... no
checking for closedir... no
checking for opendir... no
checking for readdir... no
checking for strlcat... no
checking for strlcpy... no
checking for perl5... no
checking for perl... /usr/bin/perl
checking for courier-config... /usr/bin/courier-config
checking for ltdl.h... (cached) no
configure: error: Unable to find ltdl.h. Please install Libtool's ltdl library