tclsh malloc error and what does -R do?

[Kendall Shaw]

I use -R when upgrading something with dependents, because I think it is 
going to upgrade or recompile/relink the packages that depend on what 
I'm upgrading. But, I think it just upgrades all of my outdated ports, 
is that right?

For example I used sudo port upgrade -R python24 and it upgraded most of 
my outdated ports, such as gtk2, and stopped on an error before moving 
on to the last port. So, what does -R do?

Changing the subject: When I upgrade and many ports are upgraded, the 
process often ends with this error:

tclsh(41595,0xa0081074) malloc: *** mmap(size=446464) failed (error code=12)
*** error: can't allocate region
*** set a breakpoint in malloc_error_break to debug
unable to alloc 443225 bytes
Abort trap

I don't recall if this happens also when that happens, but this time, 
just before the malloc error, I get:

Error: Variant headercache conflicts with db4
Error: Unable to open port: Error evaluating variants

The final port that was going to probably be upgraded was mutt-devel, 
which depends on db44. I don't recall if mutt was among the ports being 
upgraded whenever I got this error.

Actually, I'm not going to look at mutt now, so I've uninstalled it. 
But, do you know if the malloc error is a
general problem with upgrading many ports, or if it means my ports 
system is screwed up somehow, or if it is a problem with db44 or mutt-devel?

Kendall