Compiler Detection Fails with MS Visual Studio Build Tools 2015

I'm migrating this from a Stackoverflow post (http://stackoverflow.com/questions/43413998/cmake-with-microsoft-visual-c-build-tools) to here at the suggestion of a commenter over there. Just to add more information: my OS is Win 7 Enterprise SP1 64-bit, if that matters at all. This succeeded in a nearly identical environment with the only difference I can think of being my coworker has the full Visual Studio 2015 environment while I've only got access to the build tools.

I'm trying to build a CMake project on Windows using the MS Visual C++ Build Tools 2015 (note: not full Visual Studio). CMake, however, is apparently unable to find cl.exe

cmake ..
-- Building for: Visual Studio 14 2015
-- The C compiler identification is unknown
-- The CXX compiler identification is unknown
CMake Error at CMakeLists.txt:4 (project):
  No CMAKE_C_COMPILER could be found.



CMake Error at CMakeLists.txt:4 (project):
  No CMAKE_CXX_COMPILER could be found.

I suspect this is because CMake is expecting to find the compiler in with the Visual Studio installation but perhaps the standalone build tools install it in a different location? Is it possible to configure CMake to look elsewhere for the compiler?

To head this possibility off at the pass, cl.exe is definitely installed. When I open the Visual C++ shell (adds the tools to the path) cl.exe outputs:

cl.exe
Microsoft (R) C/C++ Optimizing Compiler Version 19.00.24210 for x86
Copyright (C) Microsoft Corporation.  All rights reserved.

usage: cl [ option... ] filename... [ /link linkoption... ]

And that is the same environment I'm running cmake .. from so cl.exe is definitely on the PATH for discovery by CMake.

Looking at the CMakeError.log file I see a couple variants of the following

Compiling the CXX compiler identification source file "CMakeCXXCompilerId.cpp" failed.
Compiler:  
Build flags: 
Id flags:  

The output was:
1
Microsoft (R) Build Engine version 14.0.25420.1
Copyright (C) Microsoft Corporation. All rights reserved.

Build started 4/14/2017 11:58:13 AM.
Project "E:\<project_dir>\build\CMakeFiles\3.8.0-rc4\CompilerIdCXX\CompilerIdCXX.vcxproj" on node 1 (default targets).
PrepareForBuild:
  Creating directory "Debug\".
  Creating directory "Debug\CompilerIdCXX.tlog\".
InitializeBuildStatus:
  Creating "Debug\CompilerIdCXX.tlog\unsuccessfulbuild" because "AlwaysCreate" was specified.
ClCompile:
  C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\CL.exe /c /nologo /W0 /WX- /Od /Oy- /D _MBCS /Gm- /EHsc /RTC1 /MDd /GS /fp:precise /Zc:wchar_t /Zc:forScope /Zc:inline /Fo"Debug\\" /Fd"Debug\vc140.pdb" /Gd /TP /analyze- /errorReport:queue CMakeCXXCompilerId.cpp
TRACKER : error TRK0002: Failed to execute command: ""C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\CL.exe" @C:\Users\<user>\AppData\Local\Temp\tmpa0925a9f05d5426d82afdcee8d722031.rsp". The operation completed successfully. [E:\<project_dir>\build\CMakeFiles\3.8.0-rc4\CompilerIdCXX\CompilerIdCXX.vcxproj]
  
  
Done Building Project "E:\<project_dir>\build\CMakeFiles\3.8.0-rc4\CompilerIdCXX\CompilerIdCXX.vcxproj" (default targets) -- FAILED.

Build FAILED.

"E:\<project_dir>\build\CMakeFiles\3.8.0-rc4\CompilerIdCXX\CompilerIdCXX.vcxproj" (default target) (1) ->
(ClCompile target) -> 
  TRACKER : error TRK0002: Failed to execute command: ""C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\CL.exe" @C:\Users\<user>\AppData\Local\Temp\tmpa0925a9f05d5426d82afdcee8d722031.rsp". The operation completed successfully. [E:\<project_dir>\build\CMakeFiles\3.8.0-rc4\CompilerIdCXX\CompilerIdCXX.vcxproj]

    0 Warning(s)
    1 Error(s)

Time Elapsed 00:00:01.21

This looks like some kind of output compatibility issue, especially the "ERROR: The operation completed successfully." lines. I'm using CMake 3.8.0-rc4 and the Visual C++ 2015 Build Tools. Any ideas?

I thought that upgrading from 3.8.0-rc4 to 3.8.0 might fix it, but no avail. I also considered that I was using 64bit CMake trying to build a 32 bit program so I changed that as well. No luck yet.

Also, for the record, this does build with CMake on a PC with full VS 2015 installed.