corosync: update RDMA support to rdma-core

The packages librdmacm and libibverbs are deprecated
and are replaced by rdma-core.

see https://github.com/NixOS/nixpkgs/issues/34314

pkgs/servers/corosync/default.nix

@@ -1,5 +1,5 @@
 { stdenv, fetchurl, makeWrapper, pkgconfig, nss, nspr, libqb
-, dbus, librdmacm, libibverbs, libstatgrab, net_snmp
+, dbus, rdma-core, libstatgrab, net_snmp
 , enableDbus ? false
 , enableInfiniBandRdma ? false
 , enableMonitoring ? false
@@ -21,7 +21,7 @@ stdenv.mkDerivation rec {
   buildInputs = [
     nss nspr libqb
   ] ++ optional enableDbus dbus
-    ++ optional enableInfiniBandRdma [ librdmacm libibverbs ]
+    ++ optional enableInfiniBandRdma rdma-core
     ++ optional enableMonitoring libstatgrab
     ++ optional enableSnmp net_snmp;
 
@@ -44,6 +44,17 @@ stdenv.mkDerivation rec {
     "LOGROTATEDIR=$(out)/etc/logrotate.d"
   ];
 
+  preConfigure = optionalString enableInfiniBandRdma ''
+    # configure looks for the pkg-config files
+    # of librdmacm and libibverbs
+    # Howver, rmda-core does not provide a pkg-config file
+    # We give the flags manually here:
+    export rdmacm_LIBS=-lrdmacm
+    export rdmacm_CFLAGS=" "
+    export ibverbs_LIBS=-libverbs
+    export ibverbs_CFLAGS=" "
+  '';
+
   postInstall = ''
     wrapProgram $out/bin/corosync-blackbox \
       --prefix PATH ":" "$out/sbin:${libqb}/sbin"