id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
13641,Boost.Build doesn't create config.log when --build-dir is specified,alexsharoff@…,Vladimir Prus,"Platform: Windows

How to reproduce:
1. Extract Boost sources to some directory, say D:\boost
2. Bootstrap Boost as usual
3. Build Boost like this: `b2 --build-dir=D:\boost-build stage`
Build process will not produce configuration log in D:\boost-build\boost\bin.v2\config.log, but will spew all configuration messages and errors to console.


What I've found:
* in tools\build\src\build-system.jam, line 678: `$(first-project-root).build-dir` yields ""/D:/boost-build/boost/bin.v2"". With a slash at the beginning it's not a valid Windows path.
* in tools\build\src\build-system.jam, line 679: `set-log-file` rule silently fails
* in tools\build\src\build\configure.jam, line 280: `FILE_OPEN` is unable to create ""/D:/boost-build/boost/bin.v2/config.log""


I don't have enough Boost.Build knowledge to provide a reasonable patch, but the problem seems to stem from `build-dir` project attribute prepending a slash to its value on Windows.
",Bugs,new,To Be Determined,build,Boost 1.66.0,Problem,,,