- if env.has_key('PCH') and env['PCH']:
- env.Depends(target, env['PCH'])
+ # Add a dependency, but only if the target (e.g. 'Source1.obj')
+ # doesn't correspond to the pre-compiled header ('Source1.pch').
+ # If the basenames match, then this was most likely caused by
+ # someone adding the source file to both the env.PCH() and the
+ # env.Program() calls, and adding the explicit dependency would
+ # cause a cycle on the .pch file itself.
+ #
+ # See issue #2505 for a discussion of what to do if it turns
+ # out this assumption causes trouble in the wild:
+ # http://scons.tigris.org/issues/show_bug.cgi?id=2505
+ if 'PCH' in env:
+ pch = env['PCH']
+ if str(target[0]) != SCons.Util.splitext(str(pch))[0] + '.obj':
+ env.Depends(target, pch)