@AF1990 try this please.

It produces the same kind of error:
Warning! Incorrect argument type specified: -with-mpi=1 --download-ptscotch --with-superlu_dist-dir=/home/franc90/code/geosx/thirdPartyLibs/install-default-release/superlu_dist --with-parmetis-dir=/home/franc90/code/geosx/thirdPartyLibs/install-default-release/parmetis --with-hypre-dir=/home/franc90/code/geosx/thirdPartyLibs/install-default-release/hypre --with-blaslapack-dir= - expecting type Bool.
And I'm not able to link the geosx executable.

Oh...duh. I put in the MKL directory and you don't have MKL....the CI tests should fail too...odd.

To be honest, I tried to remove the ${MKL_ROOT}, but the result is the same. It doesn't work.
BTW, you are right, I don't have MKL and the tests should fail!!

New error!

             Configuring PETSc to compile on your system                       
===============================================================================
*******************************************************************************
                ERROR in COMMAND LINE ARGUMENT to ./configure 
-------------------------------------------------------------------------------
The option /usr/lib/x86_64-linux-gnu/libopenblas.so should probably be /usr/lib/x86-64-linux-gnu/libopenblas.so
*******************************************************************************```

Ok, your changes fix the problem with BLAS/LAPACK, but the configure issue is still there ...
Maybe it is not possible to use PETSC_MPI_FLAG to pass several command line arguments.