Install libghc-x509-validation-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libghc-x509-validation-doc
Description:
X.509 certificate and CRL validation; documentation
X.509 certificate/CRL checks and validations routines, following RFC5280 / RFC6818. . This package provides the documentation for a library for the Haskell programming language. See http://www.haskell.org/ for more information on Haskell.
Homepage: http://github.com/vincenthz/hs-certificate
Version: 1.6.9-2build3
Section: universe/doc