diff -ruN spack-src/src/pm/hydra/configure.ac spack-src-patched/src/pm/hydra/configure.ac
--- spack-src/src/pm/hydra/configure.ac	2022-05-16 16:58:22.000000000 +0000
+++ spack-src-patched/src/pm/hydra/configure.ac	2023-07-20 15:23:21.802299913 +0000
@@ -306,15 +306,16 @@
 		    available_launchers="$available_launchers pbs"
 		    PAC_APPEND_FLAG([-ltorque],[WRAPPER_LIBS])
                 fi
-		PAC_SET_HEADER_LIB_PATH(pbs)
 		PAC_PUSH_FLAG(LIBS)
-		PAC_CHECK_HEADER_LIB(tm.h, pbs, tm_init, have_pbs_launcher=yes,
+                if test "have_pbs_launcher" = "no" ; then
+		  PAC_CHECK_HEADER_LIB(tm.h, pbs, tm_init, have_pbs_launcher=yes,
 					   have_pbs_launcher=no)
-		PAC_POP_FLAG(LIBS)
-                if test "$have_pbs_launcher" = "yes" ; then
-		    available_launchers="$available_launchers pbs"
-		    PAC_APPEND_FLAG([-lpbs],[WRAPPER_LIBS])
-                    AC_DEFINE(HAVE_PBS_PRO, 1, [Define if PBS Pro support is enabled])
+		  PAC_POP_FLAG(LIBS)
+                  if test "$have_pbs_launcher" = "yes" ; then
+		      available_launchers="$available_launchers pbs"
+		      PAC_APPEND_FLAG([-lpbs],[WRAPPER_LIBS])
+                      AC_DEFINE(HAVE_PBS_PRO, 1, [Define if PBS Pro support is enabled])
+                  fi
                 fi
 		available_rmks="$available_rmks pbs"
 		;;