more thoughts about this issue from IRC. Thanks Andreas Henriksson for the feedback.
From #debian-devel @ 2015-08-29, UTC time:
[07:32:18 PM] <ah> mapreri: experimental pbuilder works fine here....
completely unrelated I've run into issues with /dev/shm though (which was
incompletely moved to /run/shm without a compat symlink set up at /dev/shm)....
Maybe I could convince you to look into the /dev/shm related bugs... (I pretty
much suspect best thing would be to just move the mountpoint back to /dev/shm
to avoid breakage).
[07:32:39 PM] <mapreri> cool!
[07:35:27 PM] <mapreri> ah: the /{dev,run}/shm thing is something really fishy.
as you can see on bugs.d.o/pbuilder there are several related bugs. on a normal
system there is a compat symlink created by some tool i don't remember anymore,
which change behavior according to the init system and whatnot. i was thinking
about setting a /run/shm → /dev/shm symlink when USERUNSHM=yes and /dev/shm is
not already on BINDMOUNT. how does this sound?
[07:41:00 PM] <ah> mapreri: whatever works.... in my chroot the tmpfs was
mounted on /run/shm and /dev/shm was just an empty directory.... that doesn't
work..... not sure it's worth caring at all about /run/shm, but if you set up
compat symlinks then everyone should be happy.
[07:42:50 PM] <mapreri> ah: but i don't really understand is shm now expected
on /dev/shm or /run/shm? can you provide me a simple package (as in: the
builds finish in a reasonable time) that requires shm but file if only /run/shm
is present?
[07:43:51 PM] <ah> mapreri: /run/shm is a debian-sysvinit invention..... some
eager beavers started using /run/shm explicitly so I think systemd might have
shipped a /run/shm -> /dev/shm compat symlink...
[07:44:15 PM] <mapreri> it's not systemd, is something else run a boot time
[07:45:19 PM] <mapreri> it's a mess, actually, it's shell script somewhere that
do crazy check to catch weird cases i can't even think about, luckily i don't
remember where that script is anymore
[07:45:56 PM] <ah> mapreri: /usr/lib/tmpfiles.d/debian.conf creates it if you
run systemd....
[07:46:47 PM] <ah> mapreri: shell script mess sounds like the
sysvinit/initscripts opposite setup.
[07:47:20 PM] <mapreri> yeah, maybe i read the sysvinit one
[07:47:26 PM] <mapreri> wasn't aware of that file
[07:47:53 PM] <mapreri> ah: does that sounds like #591291 ?
[07:47:58 PM] -zwiebelbot- Debian#591291: pbuilder needs to mount /dev/shm -
https://bugs.debian.org/591291
[07:48:37 PM] <ah> mapreri: or #773765
[07:48:41 PM] -zwiebelbot- Debian#773765: pbuilder: Fails to mount /dev/shm in
recently created chroot (tgz) - https://bugs.debian.org/773765
[07:49:06 PM] <mapreri> there is also #717022
[07:49:10 PM] -zwiebelbot- Debian#717022: pbuilder does not mount /dev/shm in
squeeze chroots - https://bugs.debian.org/717022
[07:49:12 PM] <ah> mapreri: the newer one has some ramblings about the /run/shm
vs /dev/shm mess.
[07:49:50 PM] <ah> mapreri: that one predates the move mess... and atleast to
me it is mounted... just in the wrong location.
[07:49:56 PM] * mapreri does not like long bug logs
[07:51:27 PM] <mapreri> ah: i have a flight at 5 am to take me to my VACs, so
i'm going to do anything RSN. mind if i drop this irc stuff into #591291?
[07:51:50 PM] <ah> mapreri: feel free... no hurry.
[07:51:56 PM] <ah> mapreri: have a nice vacation
[07:51:56 PM] <mapreri> hopefully i'll wrap my mind around this issue someday
[07:52:28 PM] <mapreri> ah: FYI in jenkins.d.n we have /dev/shm in BINDMOUNDS
to workaround it
[07:52:32 PM] <ah> mapreri: IMNSHO just say no to /run/shm.... it's not like we
can ever get rid of /dev/shm anyway.
[07:53:03 PM] <mapreri> it's not that easy to do backward-incompatible changes
like this :(
[07:53:20 PM] <mapreri> people get angry if you break their setup
[07:53:44 PM] <paultag> people look for things to be angry about
[07:54:02 PM] <ah> mapreri: you're just reverting previously introduced
breakage though.. ;)
[07:54:22 PM] <mapreri> sigh
--
regards,
Mattia Rizzolo
GPG Key: 66AE 2B4A FCCF 3F52 DA18 4D18 4B04 3FCD B944 4540 .''`.
more about me: http://mapreri.org : :' :
Launchpad user: https://launchpad.net/~mapreri `. `'`
Debian QA page: https://qa.debian.org/developer.php?login=mattia `-
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