[build2] error when trying to compile build2

[Boris Kolpackov]

Phillip Shelton via users <users at build2.org> writes:

> >c:\compilers\build2_build\build2-toolchain-0.15.0-a.0.20220204083418.a451ee2a9b05\build2>build2\b-boot config.cxx=c:\compilers\mingw64\bin\g++ config.bin.lib=static build2\exe{b}
> terminate called after throwing an instance of 'butl::invalid_basic_path<char>'
>   what():  invalid filesystem path

Hm, I tried to reproduce this but could not. So there must be something
special about your environment. Could you provide more information/try
the following:

1. What version of Windows are you using? We have seen reports that
   MinGW GCC has issues with Windows 11.

2. Are you running this from the vanilla Windows Command Prompt? If not,
   could you try that?

3. I assume c:\compilers\mingw64\bin\g++ is your own MinGW GCC you've
   mentioned earlier. If so, could you try these steps with the
   "official" MinGW GCC from build2-mingw packages just to see if
   it makes a difference?