CMake: Check for existence of lsb_release

[Martyn Gigg]

A user was trying to build on a Debian release that didn't have the lsb_release command installed. CMake fails with nonsensical output

- Found the following Boost libraries:
--   date_time
--   regex
CMake Warning (dev) at Build/CMake/LinuxSetup.cmake:4 (find_package):
   Syntax Warning in cmake code at

 
/home/jwu/g/othersw/mantid-3.0.0-Source/Build/CMake/FindPythonLibs.cmake:65:34

   Argument not separated from preceding token by whitespace.
Call Stack (most recent call first):
   Build/CMake/CommonSetup.cmake:222 (include)
   CMakeLists.txt:78 (include)
This warning is for project developers.  Use -Wno-dev to suppress it.

--  DIST:  CODENAME:
CMake Error at Build/CMake/LinuxSetup.cmake:93 (if):
   if given arguments:

     "STREQUAL" "RedHatEnterprise"

   Unknown arguments specified
Call Stack (most recent call first):
   Build/CMake/CommonSetup.cmake:222 (include)
   CMakeLists.txt:78 (include)

Add detection for the command & fail gracefully if not installed.

[Martyn Gigg]

Duplicate of #8501

[Michael Reuter]

Yes, this is a duplicate.

[Stuart Campbell]

This ticket has been transferred to github issue ​9344