From https://www.postgresql.org/docs/14/install-windows-full.html --
> Both Bison and Flex are included in the msys tool suite, available from
http://www.mingw.org/wiki/MSYS as part of the MinGW compiler suite.
Aforementioned link is to a domain squatter.
Perhaps MSYS2 could be used instead? https://packages.msys2.org/base
Which is used for the official builds on EnterpriseDB?
--
Liam Bowen