debugging parallel make

[Dan McMahill]

is there an easy way to get some sort of log which clearly shows what 
commands (but not their outputs) are running at the same time during 
each part of a parallel make job?

I have something which fails to build with 'make -j2' but is fine with 
'make'.  I'm suspicious that there is an intermediate file which is used 
by more than one job at the same time and they corrupt each other but 
I'm having a hard time understanding exactly whats going on.

I'm looking for something along the lines of

[slot1] cc -c file1.c
[slot2] cc -c file2.c
[slot2] cc -c file3.c
[slot1] cc -c file4.c

where the [slot1] and [slot2] indicate which job slot is being fed a 
command.  In this example I'd see that file1 and 2 are initially being 
compiled and then when 2 finishes, file3 is being compiled.  then file1 
finishes and file4 starts.  I haven't figured out how to get this from make.

Thanks
-Dan