[CMake] CMAKE_SIZEOF_VOID_P is unset when building libgit2 on Windows

[Sebastian Schuberth]

On 3/28/2016 16:09, Brad King wrote:

>> /usr/bin/sh: -c: line 0: syntax error near unexpected token `('
>> /usr/bin/sh: -c: line 0: `C:/Ruby-DevKit/mingw/bin/gcc.exe    -fPIC
>> -o CMakeFiles/cmTC_c0166.dir/CMakeCCompilerABI.c.obj   -c \C:/Program
>> Files (x86)/CMake/share/cmake-3.5/Modules/CMakeCCompilerABI.c\'
>> CMakeFiles/cmTC_c0166.dir/build.make:65: recipe for target
>> 'CMakeFiles/cmTC_c0166.dir/CMakeCCompilerABI.c.obj' failed
>> ---8<---
>>
>> There seems to be some problem in escaping the non-alphanumeric chars
>> in the path to "CMakeCCompilerABI.c".
> 
> Strange.  CMake is regularly used from "C:/Program Files (x86)/CMake".
> 
>> Any hint how to debug this further?
> 
> Try running the logged compiler command line by hand:
> 
>    C:/Ruby-DevKit/mingw/bin/gcc.exe -c "C:/Program Files (x86)/CMake/share/cmake-3.5/Modules/CMakeCCompilerABI.c"

This seems to work, with no output on the console and an exit code of 0.

> Also try configuring a small test project in a fresh build tree:
> 
>   $ cat CMakeLists.txt
>   cmake_minimum_required(VERSION 3.5)
>   project(test C)
>   message("${CMAKE_SIZEOF_VOID_P}")
> 
> If that reproduces the problem, try configuring with --debug-trycompile
> so that the CMakeFiles/CmakeTmp/CMakeFiles/cmTC_*.dir/build.make files
> will be left behind for inspection.

Yes, that does reproduce the issue, ${CMAKE_SIZEOF_VOID_P} evaluates to an empty string. I was looking at the CMakeFiles/cmTC_21eb3.dir/build.make file for CMakeCCompilerABI but was not seeing any suspicious. Calling

$ /c/Ruby-DevKit/bin/make -f CMakeFiles/cmTC_21eb3.dir/build.make cmTC_21eb3.exe

Also successfully builds the executable.

What should I try next?

Regards,
Sebastian