Why is make not deleting intermediate files?

[Reece Hart]

Environment: Ubuntu 11.10, make 3.81

make is not deleting intermediate files when the dependency appears in
more than one rule. This occurs even when I explicitly declare the
intermediate file as such using .INTERMEDIATE with a pattern, the
literal filename, or both.

I've distilled the issue to this test case:

<<
default:
    @echo no $@ target; exit 1

oncetwice: once twice
    @echo $@: $^

## Uncommenting the following line is sufficient to cause GNU make 3.81 to
## not delete the intermediate 'twice.dep', even if it didn't exist
## previously (i.e., was created by this invocation).
#another: twice.dep

%: %.dep
    @echo $^ >$@

## the following .INTERMEDIATE has no effect re: the twice: twice.dep
## dependency
.INTERMEDIATE: %.dep
%.dep:
    @echo $@ >$@
>>

N.B. command blocks must be tab-indented.

That is, the target `once' depends on `once.dep' and `twice' depends
on `twice.dep'. In addition, `another' also depends on `twice.dep'. It
is this line that causes `twice.dep' to never be removed, even if make
created it and despite the .INTERMEDIATE line (which seems to have no
effect).

The Makefile as posted gives:

snafu$ rm -f once* twice*; make oncetwice
oncetwice: once twice
rm once.dep twice.dep

Uncommenting the twice: twice.dep line:

snafu$ rm -f once* twice*; make oncetwice
oncetwice: once twice
rm once.dep

Notice that `twice.dep' is not rm'd in the second invocation.

>From the info pages:

.INTERMEDIATE
The targets which .INTERMEDIATE depends on are treated as intermediate files.

[...]

Intermediate files are remade using their rules just like all other
files. But intermediate files are treated differently in two ways.

The first difference [...]

**The second difference is that if make does create b in order to update
something else, it deletes b later on after it is no longer
needed. Therefore, an intermediate file which did not exist before make
also does not exist after make.**


My expectation is that `twice.dep' would be deleted even without the
.INTERMEDIATE declaration, and especially with it given the info
manual description above. It appears that `twice.dep' is being treated
more like a .SECONDARY file than an intermediate.

I've tried: 1) making `another: twice.dep' a rule with a command
block; 2) variations of specifying .INTERMEDIATE as a pattern, a
literal filename, and both; 3) using .PHONY; 4) browsing make-3.82
NEWS for relevant fixes.

Thanks,
Reece