Virtual folders always empty

Hello muttkzoids, First, +1 for a great forking idea, nice combo of two excellent tools. Having a bit of trouble getting virtual folders to work though. Attempting to do <sidebar-open> always results in an empty folder, regardless of the search term. With -d3, seeing stuff like this in the debug log (apparent error noted with "==>") [ ... ] [2015-07-15 03:32:09] Reading notmuch://?query=smc... [2015-07-15 03:32:09] nm: initialize context data 0x954ce68 [2015-07-15 03:32:09] nm: reading messages...[current count=0] [2015-07-15 03:32:09] nm: db filename '/home/XXX/Mail' [2015-07-15 03:32:09] nm: db open '/home/XXX/Mail' [READ] (timeout 5) [2015-07-15 03:32:09] nm: query 'smc' [2015-07-15 03:32:09] nm: query successfully initialized [2015-07-15 03:32:09] nm: appending message, i=0, id=[...], path=[...] [2015-07-15 03:32:09] nm: allocate mx memory [2015-07-15 03:32:09] nm: initialize header data: [hdr=0x95856c0, data=0x9585328] (notmuch-sha1-[...]) [2015-07-15 03:32:09] nm: path update requested path=/home/XXX/[...], (notmuch-sha1-[ ... ]) [2015-07-15 03:32:09] nm: freeing header 0x9585328 ==> [2015-07-15 03:32:09] nm: failed to append header! [2015-07-15 03:32:09] nm: appending message, i=0, id=XXXXX, path=[...] [2015-07-15 03:32:09] parse_parameters: `charset="iso-8859-1"' [2015-07-15 03:32:09] parse_parameter: `charset' = `iso-8859-1' [2015-07-15 03:32:09] nm: initialize header data: [hdr=0x9585708, data=0x95855a8] ([ ... ] ) [2015-07-15 03:32:09] nm: path update requested path=[...] [2015-07-15 03:32:09] nm: freeing header 0x95855a8 ==> [2015-07-15 03:32:09] nm: failed to append header! [ ... ] When notmuch is executed from the commandline with the same query term, it seems to behave normally. Version info: mutt-kz 1.5.23.1 obtained via Arch AUR, configured with --enable-debug, and notmuch 0.20.1. Muttrc doesn't seem to be implicated, but for completeness, tried it with the minimal muttrc given here http://notmuchmail.org/mutttips/ and see the same problem. Any ideas on how to track this down further?