MIDI from within 32-bit chroot

owain · 2009-12-12 21:04:19

I'm wanting to use wine-pulse from AUR, within a 32-bit chroot on my 64-bit system. This is to run Finale 2009, which doesn't work with the Pulseaudio Alsa plugin when installed under bin32-wine. The problem I'm having is that nothing in the chroot can access any midi ports, with the error as follows:

$ aconnect -io
ALSA lib seq_hw.c:457:(snd_seq_hw_open) open /dev/snd/seq failed: Permission denied

Audio from the chroot, including through the Alsa driver in Wine, works OK. Is there something I need to configure or install to get this working?

PirateJonno · 2009-12-13 04:26:21

maybe timidity or something for midi support? but from the looks of that error you may need to add yourself to the 'audio' group in your chroot. if that doesn't work, do an ls -l /dev/snd/seq to see what its permissions are.

owain · 2009-12-13 11:08:43

Ah, something weird is happening with chroot. I've got the following in my .bashrc, with passwordless sudo access to chroot enabled:

alias chroot32="sudo chroot --userspec=1000 /opt/arch32 /bin/bash"

This is what happens when I use it:

$ chroot32

$ whoami
owain

$ groups
root bin daemon sys adm disk wheel log

If I then do 'su owain', everything becomes correct. Running chroot from root is also correct. Is it possible to chroot directly to a user in the way I was wanting?

PirateJonno · 2009-12-13 11:35:31

I'd imagine you could do this:

alias chroot32="sudo chroot /opt/arch32 /usr/bin/sudo -u '#1000' -s"

but you might wanna test it first, i'm no expert on chroot.

owain · 2009-12-13 12:27:11

PirateJonno wrote:

I'd imagine you could do this:
alias chroot32="sudo chroot /opt/arch32 /usr/bin/sudo -u '#1000' -s"
but you might wanna test it first, i'm no expert on chroot.

That's done the trick - thanks.

PirateJonno · 2009-12-13 14:47:53

no problem just curious, are you able to get X programs working easily with that command or do you have mess around with xhosts and whatnot? also, i'd recommend putting the full chroot command you're using in /etc/sudoers, because it could be dangerous letting any chroot command be run as root under your user (or maybe you've done that already i dunno)

owain · 2009-12-13 15:32:23

PirateJonno wrote:

no problem just curious, are you able to get X programs working easily with that command or do you have mess around with xhosts and whatnot?

They work fine

also, i'd recommend putting the full chroot command you're using in /etc/sudoers

Good point, ta

Arch Linux

#1 2009-12-12 21:04:19

MIDI from within 32-bit chroot

#2 2009-12-13 04:26:21

Re: MIDI from within 32-bit chroot

#3 2009-12-13 11:08:43

Re: MIDI from within 32-bit chroot

#4 2009-12-13 11:35:31

Re: MIDI from within 32-bit chroot

#5 2009-12-13 12:27:11

Re: MIDI from within 32-bit chroot

#6 2009-12-13 14:47:53

Re: MIDI from within 32-bit chroot

#7 2009-12-13 15:32:23

Re: MIDI from within 32-bit chroot

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