>Number:         23821
>Category:       bin
>Synopsis:       make's chdir to ./obj is undocumented
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          doc-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Dec 21 12:29:00 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     der Mouse
>Release:        1.4T, 1.6.1, probably -current
>Organization:
	Dis-
>Environment:
	Any
>Description:
	Under some circumstances, if ./obj exists, make(1) will
	silently chdir to it.  This is known to break ghostscript's
	build under at least two versions.  This is bad enough (there
	really is no reason "obj"'s mere existence should be magic when
	make is given no special options), but for the manpage to fail
	to mention it is inexcusable - especially when it is almost
	aggressively omitted; the manpage talks about MAKEOBJDIRPREFIX
	and MAKEOBJDIR, but fails to mention that if neither is set,
	./obj is used if it exists.  (If I hadn't seen the obj/
	semantics mentioned on-list, I would have been very
	hard-pressed to figure out why the build was so inexplicably
	breaking.  I probably would have had to throw a debugger at it;
	even as it was, I had to use the ktrace sledgehammer before I
	twigged to it.)

	I noticed this under 1.4T.  I confirmed its presence under
	1.6.1.  I read the code and it looks to me as though it will
	also be present in -current, though I haven't tried it there.
>How-To-Repeat:
	(This transcript from a 1.6.1 system.)
	$ cat Makefile
	foo: bar
	        mkdir -p obj
	        cp bar foo
	$ touch bar
	$ ls -ld foo bar obj
	ls: foo: No such file or directory
	ls: obj: No such file or directory
	-rw-r--r--  1 root  wheel  0 Dec 21 07:09 bar
	$ make foo
	mkdir -p obj
	cp bar foo
	$ rm foo
	$ make foo
	mkdir -p obj
	cp bar foo
	cp: bar: No such file or directory
	*** Error code 1
	
	Stop.
	make: stopped in /home/mouse
	$ 

	Then change the Makefile so the directory name is something
	else (and remove the obj/ that was created), and....

	$ cat Makefile
	foo: bar
	        mkdir -p objx
	        cp bar foo
	$ touch bar
	$ ls -ld foo bar obj objx
	ls: foo: No such file or directory
	ls: obj: No such file or directory
	ls: objx: No such file or directory
	-rw-r--r--  1 root  wheel  0 Dec 21 07:09 bar
	$ make foo
	mkdir -p objx
	cp bar foo
	$ rm foo
	$ make foo
	mkdir -p objx
	cp bar foo
	$ 

>Fix:
	Personally, I feel that for make to use ./obj in the absence of
	any explicit instruction to do so (such as an environment
	variable or a command-line flag) is a bug.  (It most certainly
	violates least surprise.)  Because I do not expect NetBSD to
	agree with this position, I have classed this as a doc-bug
	rather than a sw-bug, because the problem then becomes that
	this use of ./obj is not documented, with the fix being to
	describe the actual behaviour in the manpage.

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>Release-Note:
>Audit-Trail:
>Unformatted: