Developer tools menu has a black background

[Pierre Rudloff]

I think the background should be transparent.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: firefox 63.0+build2-0ubuntu0.18.04.2
ProcVersionSignature: Ubuntu 4.15.0-36.39-generic 4.15.18
Uname: Linux 4.15.0-36-generic x86_64
AddonCompatCheckDisabled: False
ApportVersion: 2.20.9-0ubuntu7.4
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: pierre 1697 F.... pulseaudio
BuildID: 20181023214826
Channel: Unavailable
CurrentDesktop: XFCE
Date: Wed Oct 24 22:30:54 2018
ForcedLayersAccel: False
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
IncompatibleExtensions: Default - {972ce4c6-7e08-4474-a285-3208198ce6fd}
InstallationDate: Installed on 2016-04-06 (931 days ago)
InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160323)
IpRoute:
 default via 192.168.1.1 dev wlp2s0 proto dhcp metric 600
 169.254.0.0/16 dev wlp2s0 scope link metric 1000
 192.168.1.0/24 dev wlp2s0 proto kernel scope link src 192.168.1.20 metric 600
MostRecentCrashID: bp-cf7fd7ab-ccc0-4602-903e-12ff90180908
PrefSources: prefs.js
Profiles: Profile0 (Default) - LastVersion=63.0/20181023214826 (In use)
RunningIncompatibleAddons: True
SourcePackage: firefox
UpgradeStatus: Upgraded to bionic on 2018-05-24 (153 days ago)
WifiSyslog:

dmi.bios.date: 10/21/2015
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 5.11
dmi.board.asset.tag: Tag 12345
dmi.board.name: W510LU
dmi.board.vendor: Notebook
dmi.board.version: Not Applicable
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: Notebook
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr5.11:bd10/21/2015:svnNotebook:pnW510LU:pvrNotApplicable:rvnNotebook:rnW510LU:rvrNotApplicable:cvnNotebook:ct10:cvrN/A:
dmi.product.family: Not Applicable
dmi.product.name: W510LU
dmi.product.version: Not Applicable
dmi.sys.vendor: Notebook

[Olivier Tilloy (osomon)]

Thanks for the report Pierre.

I'm not seeing this on Ubuntu 18.04 or 18.10.

Is this the only menu in firefox (or other applications) that exhibits this problem?

[Olivier Tilloy (osomon)]

Also tested in a Xubuntu 18.04 VM, not seeing the problem either.

[Pierre Rudloff (rudloff)]

It seems I can also reproduce with other menus (the main menu and the location bar menu, for example).
(I did not notice before, because I rarely use those.)

Could this be caused by my GTK theme (numix-gtk-theme)?

[Theo Linkspfeifer (lastonestanding)]

Did you disable Xfce's builtin compositor?

Settings > Windows Manager Tweaks > Compositor

[Pierre Rudloff (rudloff)]

Yes, it is disabled and if I enable it I don't have this bug anymore.
However, I would prefer to be able to leave the compositor disabled.

(Also, on another computer with Debian 9.6, I can't reproduce this bug even with the compositor disabled and the same theme.)

[Theo Linkspfeifer (lastonestanding)]

You have layers.acceleration.force-enabled set to 'true'. Does changing it back to 'false' + restart make a difference?

[Pierre Rudloff (rudloff)]

Indeed, I can't reproduce the issue anymore when it is disabled.

[Olivier Tilloy (osomon)]

Thanks for the feedback Pierre. Marking the bug invalid as the correct combination of settings makes it go away.

Hardware acceleration + no compositing is probably not a supported configuration.

[Pierre Rudloff (rudloff)]

I understand, thanks for taking the time to look at this.
I think I will leave hardware acceleration enabled because the performance gain is totally worth this small glitch.

(Also, I use hardware acceleration + no compositing on my other computers and don't have this issue, so it might be linked to a specific graphics card or driver.)