X11 app - unable to open display ""

[Ryan Schmidt]

On Apr 22, 2019, at 18:35, raf wrote:

> Thanks. I thought it might be like when -devel is added
> to a library's package name on some systems to indicate
> that it includes header files for compiling new
> programs that use the library rather than just
> containing the library itself for dynamic linking
> purposes.

It's not like that; MacPorts is not those other systems. MacPorts ports install any applicable headers or other "development" files.