ERROR: UBT ERROR: Failed to produce item: /scratch2/epic/UnrealEngine/Engine/Binaries/Linux/libUE4Editor-UnrealEd.so

My unreal engine 4.18 make command in CentOS 7 fails at this step:

[1049/1372] Link libUE4Editor-BlankModule.so
[1050/1372] Link libUE4Editor-IPC.so
[1051/1372] Link libUE4Editor-BlankPlugin.so
[1052/1372] Link libUE4Editor-XGEController.so
[1053/1372] Link libUE4Editor-SlateReflector.so
ERROR: UBT ERROR: Failed to produce item: /scratch2/epic/UnrealEngine/Engine/Binaries/Linux/libUE4Editor-UnrealEd.so
Total build time: 1554.59 seconds (Local executor: 0.00 seconds)
make: *** [UE4Editor] Error 5

any idea what has caused this and how it could be fixed?

some system information:

$ uname -a
Linux goku.bu.edu 3.10.0-862.14.4.el7.x86_64 #1 SMP Wed Sep 26 15:12:11 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
[jalal@goku UnrealEngine]$ lsb_release -a

$ lsb_release -a
LSB Version:	:core-4.1-amd64:core-4.1-noarch
Distributor ID:	CentOS
Description:	CentOS Linux release 7.5.1804 (Core) 
Release:	7.5.1804
Codename:	Core

$ clang --version
clang version 5.0.1 (tags/RELEASE_501/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/rh/llvm-toolset-7/root/usr/bin