[Boost-build] [v2] precompiled header support and parallel builds

From: Janssen, Olaf ST/HZA-TBE (janssoaf_at_[hidden])
Date: 2006-01-19 08:51:52

pch support doesn't work together with parallel builds, because access
to the precompiled header file isn't synchronized, e.g.

D:\AEAframe\Caligula\Source\Dialogs>bjam -a -j2 toolset=msvc-7.1
variant=debug
...patience...
...patience...
...patience...
...found 5179 targets...
...updating 439 targets...
msvc.compile.pch ..\..\Library\Dialogs\msvc-7.1\debug\stdafx.obj
..\..\Library\Dialogs\msvc-7.1\debug\stdafx.pch
msvc.compile.c++
..\..\Library\Dialogs\msvc-7.1\debug\BearingApproximationPropertyDialog.
obj
Stdafx.cpp
BearingApproximationPropertyDialog.cxx
..\..\Source\Dialogs\BearingApproximationPropertyDialog.cxx(26) : fatal
error C1083: Cannot open precompiled header file:
'..\..\Library\Dialogs\msvc-7.1\debug\stdafx.pch': Permission denied

Olaf