On Tue, Jan 30, 2018 at 10:03:34PM -0500, Leo Famulari wrote:
> [pid 21672] connect(3, {sa_family=AF_UNIX, sun_path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory)
> [pid 21672] close(3)                    = 0
> [pid 21672] socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
> [pid 21672] connect(3, {sa_family=AF_UNIX, sun_path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory)
> [pid 21672] close(3)                    = 0
> [pid 21672] futex(0x7f49fbe86190, FUTEX_WAKE_PRIVATE, 2147483647) = 0
> [pid 21672] rt_sigaction(SIGIO, {sa_handler=SIG_IGN, sa_mask=~[RTMIN RT_1], sa_flags=SA_RESTORER, sa_restorer=0x7f49fb8f2250}, {sa_handler=0x4096f0, sa_mask=~[KILL STOP RTMIN RT_1], sa_flags=SA_RESTORER, sa_restorer=0x7f49fb8f2250}, 8) = 0
> [pid 21672] write(4, "ptxc\0\0\0\0E\0\0\0\0\0\0\0the group `guixb"..., 96) = 96
> [pid 21672] exit_group(0)               = ?
> [pid 21672] +++ exited with 0 +++
> <... select resumed> )                  = ? ERESTARTNOHAND (To be restarted if no handler)
> --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=21672, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
> wait4(-1, NULL, WNOHANG, NULL)          = 21672
> wait4(-1, NULL, WNOHANG, NULL)          = -1 ECHILD (No child processes)
> rt_sigreturn({mask=[]})                 = -1 EINTR (Interrupted system call)
> select(4, [3], NULL, NULL, NULL

On GuixSD instead of Debian, also using core-updates, it instead
proceeds successfully like this:

52 [pid 22286] socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
53 [pid 22286] connect(3, {sa_family=AF_UNIX, sun_path="/var/run/nscd/socket"}, 110) = 0
54 [pid 22286] sendto(3, "\2\0\0\0\f\0\0\0\6\0\0\0group\0", 18, MSG_NOSIGNAL, NULL, 0) = 18
55 [pid 22286] poll([{fd=3, events=POLLIN|POLLERR|POLLHUP}], 1, 5000) = 1 ([{fd=3, revents=POLLIN|POLLHUP}])
56 [pid 22286] recvmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="", iov_len=6}, {iov_base="", iov_len=8}], msg_iovlen=2, msg_controllen=0, msg_flags=MSG_CMSG_CLOEXEC}, MSG_CMSG_C     LOEXEC) = 0
57 [pid 22286] close(3)                    = 0
58 [pid 22286] socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
59 [pid 22286] connect(3, {sa_family=AF_UNIX, sun_path="/var/run/nscd/socket"}, 110) = 0
60 [pid 22286] sendto(3, "\2\0\0\0\2\0\0\0\n\0\0\0guixbuild\0", 22, MSG_NOSIGNAL, NULL, 0) = 22
61 [pid 22286] poll([{fd=3, events=POLLIN|POLLERR|POLLHUP}], 1, 5000) = 1 ([{fd=3, revents=POLLIN|POLLHUP}])
62 [pid 22286] read(3, "\2\0\0\0\377\377\377\377\0\0\0\0\0\0\0\0\377\377\377\377\0\0\0\0", 24) = 24
63 [pid 22286] close(3)                    = 0
64 [pid 22286] open("/etc/group", O_RDONLY|O_CLOEXEC) = 3
65 [pid 22286] fstat(3, {st_dev=makedev(8, 1), st_ino=524529, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=8, st_size=550, st_atime=1517333161 /* 2018-01-     30T12:26:01.702640653-0500 */, st_atime_nsec=702640653, st_mtime=1515043935 /* 2018-01-04T00:32:15.108027808-0500 */, st_mtime_nsec=108027808, st_ctime=1515043935 /* 2018-01-04T00:32:15.1     32027927-0500 */, st_ctime_nsec=132027927}) = 0
66 [pid 22286] read(3, "root:x:0:\nwheel:x:999:leo\nusers:"..., 4096) = 550
67 [pid 22286] close(3)                    = 0