Merge branch 'hotfix_buildsys' into 'main'

Added checks in libra_build.sh to set the CC, CXX, FC and F77 env. variables

See merge request ardg/libra!154

Author: frhmadsen

scripts/libra_build.sh

@@ -136,6 +136,16 @@ if [[ -v SPACK_ROOT ]]; then
     # $SPACK_ENV gets defined in an activated env.
     SPACK_ENV_ROOT=$SPACK_ENV/.spack-env/view/
 
+    # If CUDA is installed in SPACK env., setup a symlink to libcuda.so.1 stub.
+    CUDA_LIB=`spack location -i cuda`
+    if [ -z "$CUDA_LIB" ]; then
+	echo "###Info:"
+	echo "###Info: CUDA libs not installed in $SPACK_ENV_ROOT.  Assuming a system installation.";
+	echo "###Info:"
+    else
+	ln -s $SPACK_ENV_ROOT/lib64/stubs/libcuda.so $SPACK_ENV_ROOT/lib64/libcuda.so.1
+    fi
+
     #---------------------------------------------------------
     echo "Checking required packages in SPACK ($SPACK_ROOT)"...
     #
@@ -183,11 +193,21 @@ fi
 #       GCC 11.4 with CUDA 11.x works.
 #       Not clear what other combinations work/not work.
 #
-export CXX=/usr/bin/g++
-export CC=/usr/bin/gcc
-export FC=/usr/bin/gfortran
+
+# Define compiler variables if they aren't already defined
+if [ -z "${CXX}" ]; then
+    export CXX=/usr/bin/g++
+fi
+if [ -z "${CC}" ]; then
+    export CC=/usr/bin/gcc
+fi
+if [ -z "${FC}" ]; then
+    export FC=/usr/bin/gfortran
+fi
 # GNU configure script uses the env variable F77 (for building FFTW package)
-export F77=${FC}
+if [ -z "${F77}" ]; then
+    export F77=${FCC}
+fi
 
 # 
 # Use -DLIBRA_ENABLE_CUDA_BACKEND=OFF for CPU-only build.