[3429] in Athena Bugs
Re: 6.3B: make
daemon@ATHENA.MIT.EDU (Ken Raeburn)
Sun Oct 15 17:00:31 1989
Date: Sun, 15 Oct 89 17:00:00 -0400
From: Ken Raeburn <Raeburn@MIT.EDU>
To: Richard Basch <probe@ATHENA.MIT.EDU>
Cc: bugs@ATHENA.MIT.EDU
In-Reply-To: Richard Basch's message of Sun, 15 Oct 89 10:39:09 -0400,
This often happens with rules that might not modify files.
If A depends on B, and B depends on C, but the rule for building B
from C may or may not change B (e.g., it may check to see whether the
new versions is different, and punt if not, or the rule may just be
empty), then "make -n" will show you everything, but "make" won't go
past trying to rebuild B, since if B hasn't changed, A doesn't need
rebuilding.
In the particular case you cite, y.tab.h may have been older than
awk.g.o; there was a dependency with no commands to run.
