Bug#993957:

["Adam D. Barratt" <adam@adam-barratt.org.uk>]

On Wed, 2021-09-08 at 16:58 +0100, lkcl wrote:
> schroot 1.6.10 (04 May 2014) fails with a continuous attempt to read
> a non-existent subdirectory, /run/systemd/userdb, when operating a
> type "directory" schroot.
> 

So far as I can see from the strace output you provided, that doesn't
actually appear to be the cause of the failure. Rather, this does:

> rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
> mmap(NULL, 137438957568, PROT_READ|PROT_WRITE,
> MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = -1 ENOMEM (Cannot allocate
> memory)
> brk(0x564c49ed1000)                     = 0x562c49ed1000
> mmap(NULL, 137439088640, PROT_READ|PROT_WRITE,
> MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = -1 ENOMEM (Cannot allocate
> memory)
> futex(0x7f723a5af1a0, FUTEX_WAKE_PRIVATE, 2147483647) = 0
> munmap(0x7f5239d9e000, 68719480832)     = 0
> write(2, "E: ", 3)                      = 3
> write(2, "std::bad_alloc", 14)          = 14
> write(2, "\n", 1)                       = 1
> close(4)                                = 0
> close(3)                                = 0
> exit_group(1)                           = ?
> +++ exited with 1 +++

i.e. it failed due to an unsuccessful attempt to allocate 128GB of RAM,
rather than anything to do with systemd.

Regards,

Adam