Hello, There are very few resources currently available that explain how to compile newest version of readline using MSVC toolset. I have sucessfully to do it by the build script https://github.com/jiangjianshan/msvc-pkg/blob/main/packages/readline/build.sh with other files , e.g. https://github.com/jiangjianshan/msvc-pkg/blob/main/packages/readline/001-readline-compile-on-msvc.diff in the same folder of packages/readline. If you look into the README.md of https://github.com/jiangjianshan/msvc-pkg . You can do it following way to build readline using MSVC toolset:
git clone https://github.com/jiangjianshan/msvc-pkg.git cd msvc-pkg mpt readline A good improvement of implementation of readline can be bring back Makefile.am and update the configure.ac to bring libtool macro inside. Also integrate gnulib can solve the missing posix function from MSVC. After done these, the .diff above maybe no need.