From c20d4cac1fb72afe26a3e534b92e9a9691936458 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= Date: Mon, 29 Apr 2019 21:42:04 +0200 Subject: processes: Gracefully handle daemons without clients. Fixes . Reported by Mark H Weaver . The problem could be reproduced by running, on one hand: sh -c 'exec -a guix-daemon sleep 777' and on the other hand: guix processes If there is no process with PID 777, 'guix processes' would barf as it stumbles upon a record whose client is #f. * guix/scripts/processes.scm (daemon-sessions)[child-process->session]: New procedure, with lambda formerly passed to 'map'. Handle #f returns from 'lookup-process'. Call 'child-process->session' within 'filter-map', not just 'map'. --- guix/scripts/processes.scm | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/guix/scripts/processes.scm b/guix/scripts/processes.scm index 2dd3bbf30a..a2ab017490 100644 --- a/guix/scripts/processes.scm +++ b/guix/scripts/processes.scm @@ -158,15 +158,22 @@ active sessions, and the master 'guix-daemon' process." (= pid (process-parent-id process)))) processes)) - (values (map (lambda (process) - (match (process-command process) - ((argv0 (= string->number client) _ ...) - (let ((files (process-open-files process))) - (daemon-session process - (lookup-process client) - (lookup-children (process-id process)) - (filter lock-file? files)))))) - children) + (define (child-process->session process) + (match (process-command process) + ((argv0 (= string->number client) _ ...) + (let ((files (process-open-files process)) + (client (lookup-process client))) + ;; After a client has died, there's a window during which its + ;; corresponding 'guix-daemon' process is still alive, in which + ;; case 'lookup-process' returns #f. In that case ignore the + ;; session. + (and client + (daemon-session process client + (lookup-children + (process-id process)) + (filter lock-file? files))))))) + + (values (filter-map child-process->session children) master))) (define (daemon-session->recutils session port) -- cgit v1.2.3