Hi, I get a
configure: error: Fortran 2003 Interoperability with C required, but compiler lacks support
when trying to compile a code with v11.0.069 Ifort. Would anyone know if this should be expected and what might solve this?
Not sure - what is that looking for? That message is coming from your configuration file, not Intel Fortran.
We added the C interoperability features in version 10. The current version 17 supports the Fortran 2015 "Further Interoperability with C" features. Why are you using such an old compiler, though?
GNU Configure scripts often build small test programs which they compile, run, and examine the output to determine the properties of the OS, the compiler or other prerequisite software so that a properly configured makefile can be output. Often, such scripts fail if the compiler that is to be used is more recent than the configure script.
It can be a bit difficult to hunt down the specific portion that failed, but usually if you search the configure script for the error message (or pieces of it) you will find out what happened. You can also use your shell's verbose mode by using its -v, -x or similar options.
Turns out I should have read the manual. I learned from the software developers that Fortran 2003 is required. It sounds like Ifort v11 is not 2003...
Also, from their testing they indicated that software is best run with v15. Can v15 still be purchased?
The C interoperability features of Fortran 2003 are supported in version 11, even if it doesn't have ALL of Fortran 2003. There were bugs in that support, but you haven't yet found what the configuration script is looking for.
If you buy the current version you can install and run an older version. There's no good reason to use an old, unsupported version, though, unless there are bugs in the application that are revealed by newer compilers.