When I compile our program using ifort version 126.96.36.1991 on CentOS Linux 7 on a cluster (https://documentation.sigma2.no/quick/saga.html), I get the following error:
/tmp/ifortEuRJGK.i90: catastrophic error: **Internal compiler error: segmentation violation signal raised**
The error was reproduced on a desktop with Ubuntu 18.04 and Ifort 188.8.131.5281018
The code compiles and works using GFortran.
I have not been able to reproduce the error in a minimal example, but I've made a version of the code were most is stripped away here: https://gitlab.com/rolf_h_myhre/eT/-/tree/minimal
The code compiles as is, but if line 63 in eT/src/wavefunctions/cc3/omega_cc3.F90 is uncommented, the compiler will crash.
I do not get a seg fault if the crash routine is called from the main module or
the routine does not have a generic interface or
the calling type does not extend another or
the molecular_system file is removed from the project.
When compiling the master branch of the code (https://gitlab.com/eT-program/eT) with ifort 18, I get the same error when compiling the file eT/src/solvers/tdcc/cc_propagation_class.F90.