Fix use of CLHEP to be compatible with Gaudi new cmake configuration

When using Gaudi with new CMake configuration CLHEP has to be used in a slightly different way.

This was breaking compilation with DD4hep. The problem has not been completely understood but is due to a mix of 2 ways of finding CLHEP in cmake : findCLHEP.cmake and CLHEPCondig.cmake. We now ensure that only CLHEPCondig.cmake is used.

• [2020-05-06 16:57] Validation started with lhcb-dd4hep#502
• [2020-05-07 00:11] Validation started with lhcb-dd4hep#503
• [2020-05-08 00:11] Validation started with lhcb-dd4hep#504
• [2020-05-08 10:02] Validation started with lhcb-dd4hep#505
• [2020-05-09 00:25] Validation started with lhcb-dd4hep#506
• [2020-05-12 00:14] Validation started with lhcb-dd4hep#507
• [2020-05-12 09:56] Validation started with lhcb-dd4hep#508
• [2020-05-13 00:14] Validation started with lhcb-dd4hep#509
• [2020-05-14 00:20] Validation started with lhcb-dd4hep#510
• [2020-05-15 00:18] Validation started with lhcb-dd4hep#511
• [2020-05-15 18:18] Validation started with lhcb-dd4hep#512
• [2020-05-16 00:20] Validation started with lhcb-dd4hep#513
• [2020-05-16 19:16] Validation started with lhcb-dd4hep#514
• [2020-05-17 00:13] Validation started with lhcb-dd4hep#515
• [2020-05-18 00:17] Validation started with lhcb-dd4hep#516
• [2020-05-19 00:12] Validation started with lhcb-dd4hep#517
• [2020-05-20 00:18] Validation started with lhcb-dd4hep#518
• [2020-05-20 21:30] Validation started with lhcb-dd4hep#519
• [2020-05-21 00:18] Validation started with lhcb-dd4hep#520
• [2020-05-21 18:03] Validation started with lhcb-dd4hep#521
• [2020-05-22 00:16] Validation started with lhcb-dd4hep#522
• [2020-05-22 11:28] Validation started with lhcb-dd4hep#523
• [2020-05-22 13:45] Validation started with lhcb-dd4hep#524
• [2020-05-22 14:42] Validation started with lhcb-dd4hep#525
• [2020-05-22 17:26] Validation started with lhcb-dd4hep#526
• [2020-05-23 00:14] Validation started with lhcb-dd4hep#527
• [2020-05-24 00:11] Validation started with lhcb-dd4hep#528
• [2020-05-25 00:14] Validation started with lhcb-dd4hep#529
• [2020-05-26 00:16] Validation started with lhcb-dd4hep#530
• [2020-05-27 00:15] Validation started with lhcb-dd4hep#531

added 1 commit

• 0b02b41a - Dropped double dependency breaking compilation with DD4hep

Compare with previous version

marked as a Work In Progress

added 7 commits

• 0b02b41a...98c96005 - 6 commits from branch master
• b60fe25a - Fixed CLHEP dependency in Loki as it was breaking compilation with DD4hep

Compare with previous version

unmarked as a Work In Progress

changed title from WIP: Dropped double dependency breaking compilation with DD4hep to Fixed CLHEP dependency in Loki

changed the description

• [2020-05-28 00:11] Validation started with lhcb-dd4hep#532
• [2020-05-29 00:16] Validation started with lhcb-dd4hep#533
• [2020-05-29 09:26] Validation started with lhcb-dd4hep#534
• [2020-05-30 00:19] Validation started with lhcb-dd4hep#535
• [2020-05-31 00:12] Validation started with lhcb-dd4hep#536
• [2020-06-02 00:10] Validation started with lhcb-dd4hep#537
• [2020-06-03 00:24] Validation started with lhcb-dd4hep#538
• [2020-06-04 00:18] Validation started with lhcb-dd4hep#539
• [2020-06-05 00:17] Validation started with lhcb-dd4hep#540
• [2020-06-05 08:47] Validation started with lhcb-dd4hep#541

assigned to @sponce

@sponce Could you please, add the appropriate labels to classify this MR?

added bug fix label

added Build label

resolved all threads

@jonrob the nightly appears to be fine. I will let this MR alone in the lhcb-dd4hep slot, to confirm that all the problems related to reference and VMem comes from LHCb!2579 (merged).

/ci-test --merge

assigned to @frodrigu and unassigned @sponce

added needs ref update label