On 2019-Nov-01, Fabien COELHO wrote:
> Because "cancel.h" requires PGconn declaration, thus must appear after
> "libpq-fe.h",
Then you need to add #include libpq-fe.h in cancel.h. Our policy is
that headers compile standalone (c.h / postgres_fe.h / postgres.h
excluded).
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services