Sound problems since 5.2.18

Note: target is Disco because that is what my system is on atm and it allows to check if the older virtualbox on the new env really would resolve things. I could re-install xenial/bionic later still.

I started two PPAs.
initially my expectation is that they will break badly when trying the DKMS build against the new kernel. But I can try it with mainline kernels and/or fix it up in later uploads.
First they need to build from source ...

https://launchpad.net/~paelzer/+archive/ubuntu/bionic-virtualbox-for-disco
https://launchpad.net/~paelzer/+archive/ubuntu/xenial-virtualbox-for-disco

Ok, it seems to be picky and check GCC versions in its configure, interesting.
  ** gcc version 8.8 found, expected gcc 3.x with x>1 or gcc 4.x with 0<x<10 or gcc 5.3!
  ** gcc version 9.2 found, expected gcc 4.x...7.x!

Aborting this issue in favor of a new install, not wasting time on potentially many compiler incompatibilities. :-/

The new install conformed that the version in Xenial works fine (same definition, same images).
So this definitely is an upgrade-regression from Xenial.

This might "sound" stupid but did you try different audio devices in the machine setting?

btw the compiler incompatibilities are nearly zero, you can disable that check safely (it is not intended for incompatibilities, just upstream bumps it after testing has been done)

Hi Gianfranco,
thanks for the reply - didn't know you were on this package as well.
o/

I tried different sound options on both levels:
1. I exchanged graphics cards on the Host and used the onboard sound so overal I had
  a) sound over HDMI on embedded graphics
  b) sound over HDMI on dedicated graphics
  c) sound on analog output (line out)
2. I tried various sound options
  a) SB16 (which is the default for win98 guests)
  b) AC97
  c) ICH (no luck with drivers there)

In general "windows" sounds worked e.g. wav and startup.
But all of them shared that they lost sound when the game initialized.

Now that I re-installed to 16.04 I don't need to rebuild things as before.
I have a working environment and when time permits I wanted to slowly pull in the virtualbox releases of bionic-release, bionic-updates, ...
Consider it a poor mans binary search so that we'd have a starting point or better a smaller version range to look for.
Lets mark it incomplete until I provided that.

Can't you just try the upstream releases?
https://download.virtualbox.org/virtualbox/
they provide xenial binaries up to the latest version...

I knew from my upgrading:
5.1.38-dfsg-0ubuntu1.16.04.3 (xenial) ok
5.2.32-dfsg-0~ubuntu18.04.1 (bionic) - fail
6.0.6-dfsg-1 (disco) - fail
I think but I'm not sure Bionic release (5.2.10 worked as well)

So I started a poor mans binary search with the upstream packages.
5.2_5.2.32-132073 - fail
5.2_5.2.28-130011 - fail
5.2_5.2.20-125813 - fail
5.2_5.2.16-123759 - ok
5.2_5.2.14-123301 - ok
5.2_5.2.4-119785 - dkms error on install
5.5.2_2.0-118431 - dkms error on install
---
5.1_5.1.38-122592 - ok

Unfortunately time ran out then .18 or .20 is the breaking point.
I can easily check that out next time.

But once I do so is there a common best practice to collect debug info to report that maybe upstream?

Or does that version level already ring a bell?

thanks for the debug! lets see changelog:

 VirtualBox 5.2.20 (released October 16 2018)

This is a maintenance release. The following items were fixed and/or added:

    VMM: fixed task switches triggered by INTn instruction (bug #17979)
    Storage: fixed connecting to certain iSCSI targets (bug #17507)
    Storage: fixed handling of flush requests when configured to be ignored when the host I/O cache is used (bug #17573)
    Drag and drop: implemented support for UNC paths (bug #17146)
    Drag and drop: fixed resuming operation when restoring from a saved state (bug #17649)
    Drag and drop: fixed copying files with long file names (> 248 characters) from guests to Windows hosts (bug #17447)
    Drag and drop: fixed handling files with Unicode names on Windows guests (bug #15501)
    Drag and drop: fixed copying empty (0-byte) files to / from guests (bugs #14863 + #17443)
    Drag and drop: fixed copying over files from hosts to Linux guests (bug #16025)
    Networking: restore connectivity for guests bridged to host adapters that were unavailable temporarily (Windows hosts, bug #17090)
    Guest Control: fixed hang when using --wait-stdout and/or --wait-stderr (bug #17386). Needs updating Guest Additions
    Video recording: fixed starting video recording on VM power up (bug #17307)
    Linux Additions: various build fixes for kernel modules on recent distributions, and made sure modules end up in initramfs files
    Linux Additions: build fixes for 4.19, thank you Larry Finger
    Linux Additions: various small fixes for video driver

VirtualBox 5.2.18 (released August 14 2018)

This is a maintenance release. The following items were fixed and/or added:

    VMM: See user manual.
    VMM: fix loading with recent binutils and self-built versions of VirtualBox (bug #17851)
    NAT: fix --nataliasmode sameports which is a valid setting (bug #13000)
    VRDP: fixed VM process termination on RDP client disconnect if 3D is enabled for the virtual machine

looks like nothing has changed in that timeframe... I'll look at the code

Audio changed in the code, it would be nice to understand which version exactly broke it (if 5.2.18 or 5.2.20), and then open a ticket upstream!

In the meanwhile I'll prod them to this bug

If anything of the list that you provided then I'd say
  "Linux Additions: various small fixes for video driver"

I should later today get to test .18 and .20 ...

5.2.18 is good as well, therefore 5.2.20 is the breaking version.

Reference: https://www.virtualbox.org/ticket/18879

Reminder for myself, got pinged by Gianfranco that 6.0.12 has some audio fixes worth to try.

TBH 6.0.12 doesn't work at all.
Just get this without any window popping up

$ sudo virtualbox
[sudo] password for paelzer:
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 395, resource id: 14680068, major code: 2 (ChangeWindowAttributes), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 396, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 397, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 398, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 400, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 401, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 402, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 405, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 406, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 407, resource id: 14680068, major code: 2 (ChangeWindowAttributes), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 408, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 409, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 410, resource id: 14680068, major code: 20 (GetProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 414, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 415, resource id: 14680068, major code: 19 (DeleteProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 418, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 419, resource id: 14680068, major code: 129 (Unknown), minor code: 2
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 420, resource id: 14680068, major code: 19 (DeleteProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 423, resource id: 14680068, major code: 18 (ChangeProperty), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 440, resource id: 14680068, major code: 2 (ChangeWindowAttributes), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 441, resource id: 14680068, major code: 2 (ChangeWindowAttributes), minor code: 0
Qt WARNING: QXcbConnection: XCB error: 3 (BadWindow), sequence: 442, resource id: 14680068, major code: 20 (GetProperty), minor code: 0
...

Tried the new 6.0.14
=> hangs on start just as 6.0.12 did :-/

It was mentioned that something new would be in proposed but all I see is the former 5.1.38-dfsg-0ubuntu1.16.04.3 that is already in updates.

Is virtualbox building fine from source usually?
Any pointers to source and build howto?
Because I could then slowly grind my way to bisect this issue to identify what broke it between 5.2.18 and 5.2.20.

yes, it should just build fine from source!

I beg your pardon,
I fail to find 5.2.18 / 5.2.20 in either
https://github.com/mirror/vbox
or
https://www.virtualbox.org/browser/vbox/trunk

Do you have a pointer where to start for building/bisecting this?