libreadline.so.6: cannot open shared object file. Have libreadline-7 and dev

Im getting the error below while trying to run vtysh for some network simulations

vtysh: error while loading shared libraries: libreadline.so.6: cannot open shared object file: No such file or directory

Currently I have libreadline-dev and libreadline-7 installed, and made a symlink that points to libreadline.so.7 at /lib/x86_64-linux-gnu/libreadline.so.6 but to no avail. I'm assuming it might be looking for a different path, but I'm not sure how to approach troubleshooting problems like these. ------------------------- No such luck with the suggestions below. After compiling readline6.3 from the source code as suggested below, my output from ldconfig -v | grep readline is:

/sbin/ldconfig.real: Can't stat /usr/local/lib/x86_64-linux-gnu: No such file or directory
/sbin/ldconfig.real: Path `/lib/x86_64-linux-gnu' given more than once
/sbin/ldconfig.real: Path `/usr/lib/x86_64-linux-gnu' given more than once
	libreadline.so.6 -> libreadline.so.6.3
	libreadline.so.7 -> libreadline.so.7.0
/sbin/ldconfig.real: /lib/x86_64-linux-gnu/ld-2.27.so is the dynamic linker, ignoring

	libguilereadline-v-18.so.18 -> libguilereadline-v-18.so.18.0.0
/home/gdc/Desktop/readline-6.3:
/sbin/ldconfig.real: /lib32/ld-2.27.so is the dynamic linker, ignoring