I see libpq5 in the repository but not its counterpart libpq-devel. Why is there no corresponding devel-package? Normally they always go together. Otherwise I see not much sense in distributing a shared library you can’t link to in your code.
There is libpqxx-devel though but I can’t make use of it since my app is not a C++ one.
UPD: I see that version-specofoc postgresqlNN-devel packages are available, will try them, perhaps this is the answer.