ExaGO fails to build: Missing HSL

[pelesh]

When building with clang I get following link error:

[ 56%] Linking CXX executable opflow
ld.lld: error: undefined symbol: mc19ad_
>>> referenced by IpEquilibrationScaling.cpp
>>>               IpEquilibrationScaling.o:(Ipopt::EquilibrationScaling::DetermineScalingParametersImpl(Ipopt::SmartPtr<Ipopt::VectorSpace const>, Ipopt::SmartPtr<Ipopt::VectorSpace const>, Ipopt::SmartPtr<Ipopt::VectorSpace const>, Ipopt::SmartPtr<Ipopt::MatrixSpace const>, Ipopt::SmartPtr<Ipopt::MatrixSpace const>, Ipopt::SmartPtr<Ipopt::SymMatrixSpace const>, Ipopt::Matrix const&, Ipopt::Vector const&, Ipopt::Matrix const&, Ipopt::Vector const&, double&, Ipopt::SmartPtr<Ipopt::Vector>&, Ipopt::SmartPtr<Ipopt::Vector>&, Ipopt::SmartPtr<Ipopt::Vector>&)) in archive /lustre/orion/eng145/world-shared/spack-install/linux-sles15-x86_64/clang-16.0.0-rocm5.6.0-mixed/ipopt-3.12.10-7fp33q627rou44fzquk57llhwoqqeuho/lib/libipopt.a

It seems HSL is not found. This is for clean checkout of develop on Frontier. I can seeHSL module loaded:

$ ml

Currently Loaded Modules:
...
 34) coinhsl/2019.05.21-gcc-12.2.0-mixed-and6kty
 35) hipblas/5.6.0-clang-16.0.0-rocm5.6.0-mixed-pgkobjo

I used following command to build (all defaults):

$ CC=clang CXX=clang++ FC=flang cmake ../exago
$ make

Originally posted by @pelesh in #126 (comment)

[pelesh]

Additional info -- if I enable GPU support, this problem is gone. It looks as if there is a bug in CMake that enables Fortran support only if GPU support is enabled, as well.

CC @cameronrutherford @nkoukpaizan