"Fatal trap 12: page fault while in kernel mode" in mmap()

A package build machine just died with the following:

Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0x6c
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc06cf6e0
stack pointer           = 0x10:0xe32c9c70
frame pointer           = 0x10:0xe32c9ce4
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 76798 (javadoc)
kernel: type 12 trap, code=0

mmap(c7c65bd0,e32c9d14,20,434,8) at mmap+0x2a0
syscall(805002f,280f002f,bfbf002f,8059330,825a415) at syscall+0x2a0
Xint0x80_syscall() at Xint0x80_syscall+0x1d
--- syscall (198, FreeBSD ELF32, nosys), eip = 0x281785a4, esp = 0xbfbfd80c, ebp = 0xbfbfd858 ---