Mike Ainsworth wrote:
I suspect I must be getting something fairly basic wrong, but I can't even get an example from the GPC documentation to build successfully!
The part of the documentation you are referring to is marked "outdated". What you tried to compile is a "somewhat simpler GPC-specific module" which was supported by older versions of GPC, is currently unsupported but might be reanimated as the PXSC-style module.
GPC supports ISO-10206 Extended-Pascal modules as well as UCSD Pascal units, which I prefer. (The latter ones are popular because they are also supported by Borland Pascal.)
Hope this helps,
Peter