Seeing the same behaviour currently. pselect6(0, NULL, NULL, NULL, {tv_sec=0, tv_nsec=20000}, NULL) = 0 (Timeout) robertc@robertc-xps:~$ sudo snap debug stacktraces goroutine 788 [running]: github.com/snapcore/snapd/daemon.getStacktraces(0xc42042a1d0, 0xb) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/daemon/api_debug_stacktrace.go:29 +0x76 github.com/snapcore/snapd/daemon.postDebug(0x562917885b60, 0xc4206e4c00, 0x0, 0x0, 0x0) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/daemon/api_debug.go:344 +0x37a github.com/snapcore/snapd/daemon.(*Command).ServeHTTP(0x562917885b60, 0x56291742f140, 0xc4205ee420, 0xc4206e4c00) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/daemon/daemon.go:167 +0x3fd github.com/snapcore/snapd/vendor/github.com/gorilla/mux.(*Router).ServeHTTP(0xc42014e000, 0x56291742f140, 0xc4205ee420, 0xc4206e4900) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/vendor/github.com/gorilla/mux/mux.go:212 +0xcf github.com/snapcore/snapd/daemon.logit.func1(0x56291742f980, 0xc4201536c0, 0xc4206e4900) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/daemon/daemon.go:214 +0xdf net/http.HandlerFunc.ServeHTTP(0xc420594580, 0x56291742f980, 0xc4201536c0, 0xc4206e4900) /usr/lib/go-1.10/src/net/http/server.go:1947 +0x46 net/http.serverHandler.ServeHTTP(0xc420435930, 0x56291742f980, 0xc4201536c0, 0xc4206e4900) /usr/lib/go-1.10/src/net/http/server.go:2697 +0xbe net/http.(*conn).serve(0xc4209ac320, 0x562917430880, 0xc4204046c0) /usr/lib/go-1.10/src/net/http/server.go:1830 +0x653 created by net/http.(*Server).Serve /usr/lib/go-1.10/src/net/http/server.go:2798 +0x27d goroutine 1 [select, 317 minutes]: main.run(0xc4202a96e0, 0x0, 0x0) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/cmd/snapd/main.go:153 +0x501 main.main() /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/cmd/snapd/main.go:64 +0x10d goroutine 5 [syscall, 317 minutes]: os/signal.signal_recv(0x0) /usr/lib/go-1.10/src/runtime/sigqueue.go:139 +0xa8 os/signal.loop() /usr/lib/go-1.10/src/os/signal/signal_unix.go:22 +0x24 created by os/signal.init.0 /usr/lib/go-1.10/src/os/signal/signal_unix.go:28 +0x43 goroutine 10 [select, 317 minutes, locked to thread]: runtime.gopark(0x56291741e780, 0x0, 0x562916d20415, 0x6, 0x18, 0x1) /usr/lib/go-1.10/src/runtime/proc.go:291 +0x120 runtime.selectgo(0xc42005a750, 0xc42039efc0) /usr/lib/go-1.10/src/runtime/select.go:392 +0xe56 runtime.ensureSigM.func1() /usr/lib/go-1.10/src/runtime/signal_unix.go:549 +0x1f6 runtime.goexit() /usr/lib/go-1.10/src/runtime/asm_amd64.s:2361 +0x1 goroutine 53 [IO wait, 316 minutes]: internal/poll.runtime_pollWait(0x7fa74c12bf00, 0x72, 0x0) /usr/lib/go-1.10/src/runtime/netpoll.go:173 +0x59 internal/poll.(*pollDesc).wait(0xc420136318, 0x72, 0xc4202de000, 0x0, 0x0) /usr/lib/go-1.10/src/internal/poll/fd_poll_runtime.go:85 +0x9d internal/poll.(*pollDesc).waitRead(0xc420136318, 0xffffffffffffff00, 0x0, 0x0) /usr/lib/go-1.10/src/internal/poll/fd_poll_runtime.go:90 +0x3f internal/poll.(*FD).Accept(0xc420136300, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0) /usr/lib/go-1.10/src/internal/poll/fd_unix.go:372 +0x1aa net.(*netFD).accept(0xc420136300, 0xc42006cdd0, 0xc420198750, 0x56291741e8b0) /usr/lib/go-1.10/src/net/fd_unix.go:238 +0x44 net.(*UnixListener).accept(0xc420173ef0, 0x562916d097c0, 0xc420030010, 0xc4204158c0) /usr/lib/go-1.10/src/net/unixsock_posix.go:162 +0x34 net.(*UnixListener).Accept(0xc420173ef0, 0xc420588140, 0xc42006ce50, 0x562916d1503a, 0xc420030010) /usr/lib/go-1.10/src/net/unixsock.go:253 +0x4b github.com/snapcore/snapd/daemon.(*ucrednetListener).Accept(0xc420173f80, 0x0, 0x0, 0x0, 0x0) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/daemon/ucrednet.go:112 +0x4f net/http.(*Server).Serve(0xc420435930, 0x56291742f100, 0xc420173f80, 0x0, 0x0) /usr/lib/go-1.10/src/net/http/server.go:2773 +0x1a7 github.com/snapcore/snapd/daemon.(*Daemon).Start.func1.1(0x56291679a12b, 0xc42008c180) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/daemon/daemon.go:371 +0x4b github.com/snapcore/snapd/vendor/gopkg.in/tomb%!e(MISSING)v2.(*Tomb).run(0xc420430050, 0xc420298000) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/vendor/gopkg.in/tomb.v2/tomb.go:163 +0x2d created by github.com/snapcore/snapd/vendor/gopkg.in/tomb%!e(MISSING)v2.(*Tomb).Go /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/vendor/gopkg.in/tomb.v2/tomb.go:159 +0xbb goroutine 22 [select, 2 minutes]: github.com/snapcore/snapd/overlord/standby.(*StandbyOpinions).Start.func1(0xc420432fa0) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/overlord/standby/standby.go:104 +0x142 created by github.com/snapcore/snapd/overlord/standby.(*StandbyOpinions).Start /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/overlord/standby/standby.go:97 +0xb6 goroutine 24 [select, 2 minutes]: github.com/snapcore/snapd/overlord.(*Overlord).Loop.func1(0x0, 0x0) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/overlord/overlord.go:445 +0x196 github.com/snapcore/snapd/vendor/gopkg.in/tomb%!e(MISSING)v2.(*Tomb).run(0xc420432000, 0xc420594600) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/vendor/gopkg.in/tomb.v2/tomb.go:163 +0x2d created by github.com/snapcore/snapd/vendor/gopkg.in/tomb%!e(MISSING)v2.(*Tomb).Go /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/vendor/gopkg.in/tomb.v2/tomb.go:159 +0xbb goroutine 25 [IO wait]: internal/poll.runtime_pollWait(0x7fa74c12be30, 0x72, 0x0) /usr/lib/go-1.10/src/runtime/netpoll.go:173 +0x59 internal/poll.(*pollDesc).wait(0xc420136218, 0x72, 0xc4203a1f00, 0x0, 0x0) /usr/lib/go-1.10/src/internal/poll/fd_poll_runtime.go:85 +0x9d internal/poll.(*pollDesc).waitRead(0xc420136218, 0xffffffffffffff00, 0x0, 0x0) /usr/lib/go-1.10/src/internal/poll/fd_poll_runtime.go:90 +0x3f internal/poll.(*FD).Accept(0xc420136200, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0) /usr/lib/go-1.10/src/internal/poll/fd_unix.go:372 +0x1aa net.(*netFD).accept(0xc420136200, 0xc4201c7dd0, 0xc420198750, 0x56291741e8b0) /usr/lib/go-1.10/src/net/fd_unix.go:238 +0x44 net.(*UnixListener).accept(0xc420173e30, 0x562916d097c0, 0xc420030010, 0xc4204158c0) /usr/lib/go-1.10/src/net/unixsock_posix.go:162 +0x34 net.(*UnixListener).Accept(0xc420173e30, 0xc4205ee360, 0xc4201c7e50, 0x562916d1503a, 0xc420030010) /usr/lib/go-1.10/src/net/unixsock.go:253 +0x4b github.com/snapcore/snapd/daemon.(*ucrednetListener).Accept(0xc420173f20, 0x0, 0x0, 0x0, 0x0) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/daemon/ucrednet.go:112 +0x4f net/http.(*Server).Serve(0xc420435930, 0x56291742f100, 0xc420173f20, 0x0, 0x0) /usr/lib/go-1.10/src/net/http/server.go:2773 +0x1a7 github.com/snapcore/snapd/daemon.(*Daemon).Start.func1(0x0, 0x0) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/daemon/daemon.go:379 +0x58 github.com/snapcore/snapd/vendor/gopkg.in/tomb%!e(MISSING)v2.(*Tomb).run(0xc420430050, 0xc420030ab0) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/vendor/gopkg.in/tomb.v2/tomb.go:163 +0x2d created by github.com/snapcore/snapd/vendor/gopkg.in/tomb%!e(MISSING)v2.(*Tomb).Go /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/vendor/gopkg.in/tomb.v2/tomb.go:159 +0xbb goroutine 26 [select, 2 minutes]: main.runWatchdog.func1(0xc420433090, 0xc420430000) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/cmd/snapd/main.go:93 +0xff created by main.runWatchdog /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/cmd/snapd/main.go:91 +0x22d goroutine 80 [select, 22 minutes]: github.com/snapcore/snapd/overlord/ifacestate/udevmonitor.(*Monitor).Run.func1(0x562916480ffa, 0x56291741e618) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/overlord/ifacestate/udevmonitor/udevmon.go:147 +0x35a github.com/snapcore/snapd/vendor/gopkg.in/tomb%!e(MISSING)v2.(*Tomb).run(0xc4204465a0, 0xc4208eeec0) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/vendor/gopkg.in/tomb.v2/tomb.go:163 +0x2d created by github.com/snapcore/snapd/vendor/gopkg.in/tomb%!e(MISSING)v2.(*Tomb).Go /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/vendor/gopkg.in/tomb.v2/tomb.go:159 +0xbb goroutine 29 [syscall]: syscall.Syscall6(0x17, 0x9, 0xc4201c4e38, 0x0, 0x0, 0x0, 0x0, 0xc4202adc80, 0xc4201c4dc0, 0x562916481b2b) /usr/lib/go-1.10/src/syscall/asm_linux_amd64.s:44 +0x5 syscall.Select(0x9, 0xc4201c4e38, 0x0, 0x0, 0x0, 0x0, 0xc4201c4e60, 0x562916478206) /usr/lib/go-1.10/src/syscall/zsyscall_linux_amd64.go:1367 +0xb0 github.com/snapcore/snapd/osutil/udev/netlink.stopperSelectReadable(0x4, 0x8, 0xc42024c190, 0x46, 0xc4203bbf20) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/osutil/udev/netlink/rawsockstop.go:57 +0x160 github.com/snapcore/snapd/osutil/udev/netlink.RawSockStopper.func1(0xc42031ec60, 0xc4205b1f38, 0x6) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/osutil/udev/netlink/rawsockstop.go:31 +0x43 github.com/snapcore/snapd/osutil/udev/netlink.(*UEventConn).Monitor.func4(0xc42031ec80, 0xc42094c4e0, 0xc42094c540, 0xc42094c5a0, 0xc4200c73c0, 0x562917432000, 0xc42031ec60, 0xc42094c480) /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/osutil/udev/netlink/conn.go:139 +0x3e created by github.com/snapcore/snapd/osutil/udev/netlink.(*UEventConn).Monitor /build/snapd/parts/snapd-deb/build/_build/src/github.com/snapcore/snapd/osutil/udev/netlink/conn.go:136 +0x233 goroutine 789 [syscall]: syscall.Syscall(0x0, 0x3, 0xc42086e1f1, 0x1, 0xc4205dc600, 0xc4202bc000, 0xc420990dd8) /usr/lib/go-1.10/src/syscall/asm_linux_amd64.s:18 +0x5 syscall.read(0x3, 0xc42086e1f1, 0x1, 0x1, 0xc4202bc000, 0x0, 0x0) /usr/lib/go-1.10/src/syscall/zsyscall_linux_amd64.go:749 +0x61 syscall.Read(0x3, 0xc42086e1f1, 0x1, 0x1, 0xc420432230, 0x0, 0xc4205c2400) /usr/lib/go-1.10/src/syscall/syscall_unix.go:162 +0x4b internal/poll.(*FD).Read(0xc420acc280, 0xc42086e1f1, 0x1, 0x1, 0x0, 0x0, 0x0) /usr/lib/go-1.10/src/internal/poll/fd_unix.go:153 +0x11a net.(*netFD).Read(0xc420acc280, 0xc42086e1f1, 0x1, 0x1, 0x4, 0xc420990f18, 0x56291648b643) /usr/lib/go-1.10/src/net/fd_unix.go:202 +0x51 net.(*conn).Read(0xc4208080e0, 0xc42086e1f1, 0x1, 0x1, 0x0, 0x0, 0x0) /usr/lib/go-1.10/src/net/net.go:176 +0x6c net/http.(*connReader).backgroundRead(0xc42086e1e0) /usr/lib/go-1.10/src/net/http/server.go:668 +0x5c created by net/http.(*connReader).startBackgroundRead /usr/lib/go-1.10/src/net/http/server.go:664 +0xd0