[mfem] Add a method to resolve all header dependencies of a spec using its

link dependencies. Use the new method for hipblas.

[petsc] Add new variant, fortran-bindings, which is propagated to the
        petsc configuration via the option with the same name.

var/spack/repos/builtin/packages/mfem/package.py

@@ -1004,7 +1004,7 @@ def find_optional_library(name, prefix):
             if "^hipblas" in spec:  # hipblas is needed @4.8.0:+rocm
                 # note: superlu-dist+rocm needs the hipblas header path too
                 hipblas = spec["hipblas"]
-                hip_headers += hipblas.headers
+                hip_headers += self.all_headers(hipblas)
                 hip_libs += hipblas.libs
             if "%cce" in spec:
                 # We assume the proper Cray CCE module (cce) is loaded:
@@ -1405,3 +1405,12 @@ def ld_flags_from_dirs(self, pkg_dirs_list, pkg_libs_list):
         flags += ["-L%s" % dir for dir in pkg_dirs_list if not self.is_sys_lib_path(dir)]
         flags += ["-l%s" % lib for lib in pkg_libs_list]
         return " ".join(flags)
+
+    def all_headers(self, root_spec):
+        all_hdrs = HeaderList([])
+        for dep in root_spec.traverse(deptype="link"):
+            try:
+                all_hdrs += root_spec[dep.name].headers
+            except NoHeadersError:
+                pass
+        return all_hdrs

var/spack/repos/builtin/packages/petsc/package.py

@@ -263,6 +263,9 @@ class Petsc(Package, CudaPackage, ROCmPackage):
     variant("hwloc", default=False, description="Activates support for hwloc")
     variant("kokkos", default=False, description="Activates support for kokkos and kokkos-kernels")
     variant("fortran", default=True, description="Activates fortran support")
+    variant(
+        "fortran-bindings", default=True, when="+fortran", description="Activates fortran bindings"
+    )
 
     with when("+rocm"):
         # https://github.com/spack/spack/issues/37416
@@ -503,6 +506,8 @@ def mpi_dependent_options(self):
             ]
             if "+fortran" in self.spec:
                 compiler_opts.append("--with-fc=%s" % os.environ["FC"])
+                fb = "1" if self.spec.satisfies("+fortran-bindings") else "0"
+                compiler_opts.append(f"--with-fortran-bindings={fb}")
             else:
                 compiler_opts.append("--with-fc=0")
         else:
@@ -512,6 +517,8 @@ def mpi_dependent_options(self):
             ]
             if "+fortran" in self.spec:
                 compiler_opts.append("--with-fc=%s" % self.spec["mpi"].mpifc)
+                fb = "1" if self.spec.satisfies("+fortran-bindings") else "0"
+                compiler_opts.append(f"--with-fortran-bindings={fb}")
             else:
                 compiler_opts.append("--with-fc=0")
             if self.spec.satisfies("%intel"):