Libgc: why is this code leaking?

I tried using libgc (BDW garbage collector) inside this simple code.

Note that this link is only kept for the last node in the bogus "list", so the live set is only the last two nodes.

// thanks to @chill for this example
#include <gc.h>

struct list {
    struct list* next;
};

int main() {
    GC_INIT();
    struct list *last = NULL;
    for (;;) {
        struct list* nuo = GC_MALLOC(sizeof(struct list));
        nuo->next = NULL;
        // if next line is commented, then no leakage
        if (last) last->next = nuo;
        last = nuo;
    }
}

      

        
        
        
      

    

But it cannot stay within memory:

$ gcc -O0 gc.c -lgc -o gc

$ GC_MAXIMUM_HEAP_SIZE = 100000000./gc

GC Warning: Out of Memory!  Trying to continue ...
GC Warning: Out of Memory!  Trying to continue ...
GC Warning: Out of Memory!  Trying to continue ...
GC Warning: Out of Memory!  Trying to continue ...
GC Warning: Out of Memory! Heap size: 95 MiB. Returning NULL!
Segmentation fault

      

        
        
        
      

    

How am I wrong? Ubuntu 15.04 x86_64 gcc 4.9.2 libgc 7.2d-6.4

Update: I just compiled the trunk version from https://github.com/ivmai/bdwgc and it looks correct. So the bug is only in 7.2d or in the version packaged in Ubuntu.

Update: libgc 7.2f compiled from source also works correctly. So this is just a problem with the Ubuntu and Debian version.