I cleaned all the previously compiled output and recompiled C::B, and the last two sentences of build log are:
Process terminated with status 0 (56 minutes, 41 seconds)
50 errors, 4744 warnings
But then I press CTRL-F9 to compile it again without clean the previously compiled output, it said:
Process terminated with status 0 (0 minutes, 14 seconds)
0 errors, 0 warnings
The attachments are two build log. The first one is with error message, and the second one is the log of recompiling.
[attachment deleted by admin]