Comment 61 for bug 1751460

Jeremy, here's some debug you could try adding to Source/bmalloc/bmalloc/VMAllocate.h:

// At the top of the file, before the bmalloc namespace
#include <cstring>
#include <errno.h>

inline void* tryVMAllocate(size_t vmSize)
{
    vmValidate(vmSize);
    void* result = mmap(0, vmSize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON | BMALLOC_NORESERVE, BMALLOC_VM_TAG, 0);
    if (result == MAP_FAILED)
{
WTFLogAlways("%s: mmap failed: %d (%s)", __FUNCTION__, errno, strerror(errno));
        return nullptr;
}
    return result;
}

That would tell us which of the many possible errors are occurring here.

And if you need an immediate workaround, you can of course build with -DUSE_SYSTEM_MALLOC=ON. That will be bad, so I can't recommend that... but you're already disabling GStreamerGL and web fonts.... :P