Nixpkgs: Pantheon: screenshots are darker when selecting the area

[davidak]

Describe the bug
When i create a screenshot using PRINT key, it's as expected.

But when i select an area, it is darker.

Not when i select a window.

To Reproduce
Steps to reproduce the behavior:

1. use pantheon desktop
2. snapshot using SHIFT + PRINT
3. see snapshot

Expected behavior
image not altered

Additional context
was not an issue in 20.03

Notify maintainers
@worldofpeace

Metadata

• system: "x86_64-linux"
• host os: Linux 5.8.13, NixOS, 20.09beta992.7badbf18c45 (Nightingale)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.7
• channels(root): "home-manager-20.09, nixos-20.09beta992.7badbf18c45, nixos-hardware, nixos-unstable-21.03pre246062.420f89ceb26"
• nixpkgs: /home/davidak/.cache/nixpkgs-review/pr-99931/nixpkgs

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module:

[davidak]

This seems to be fixed after an update.

• system: "x86_64-linux"
• host os: Linux 5.8.14, NixOS, 20.09beta1057.0b8799ecaaf (Nightingale)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.7
• channels(root): "home-manager-20.09, nixos-20.09beta1057.0b8799ecaaf, nixos-hardware, nixos-unstable-21.03pre246062.420f89ceb26"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

[davidak]

Oh noooooooooooooooooooooooooooooooo it's there again.

[davidak]

I guess the dark space is the selection that is not removed quickly enough, so it is a timing issue. You can even see the border in the screenshot!

@worldofpeace can you reproduce it? don't happen always, but in 3 of 5 cases...

this is a blocker for me since my work involves taking screenshots a lot. i don't want it to block the release, but it has higher priority than the other issues i reported

still happens in latest 20.09beta1322.ba2ec4867d7

[worldofpeace]

I've never had this issue. This has to do with the screenshot window timeouts, see these issues https://github.com/elementary/screenshot/issues/50 https://github.com/elementary/gala/issues/211. In the issue for gala someone was actually able to reproduce it recently https://github.com/elementary/gala/issues/211#issuecomment-705239902.
The issue here is, pantheon's development is steered to their upcoming release. So gala master and screenshot master are way ahead. So we'd have to try to reproduce on those, but currently gala master doesn't build https://github.com/elementary/gala/issues/915. I intend to fix that issue but I have too much to do sometimes.

[worldofpeace]

Opened a PR to fix that in gala https://github.com/elementary/gala/pull/945

[davidak]

Great. The PR was merged. Do you plan to backport it?

[worldofpeace]

Great. The PR was merged. Do you plan to backport it?

I'd doesn't fix this exact issue. Currently those other reports I linked prove that the current state is a regression, or on your machine the timeout isn't sufficent

[davidak]

Just checked. This issue is not present in NixOS 20.03.3185.6b5f85a62c4.