2021765 - Error: Could not get children of `(profile)\thumbnails' after first installing Firefox

Status: RESOLVED FIXED

(Firefox :: New Tab Page, defect)

Description

[Fedde westra]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36 Edg/146.0.0.0

Steps to reproduce:

litterly nothing i did:
maybe you need to reproduce the installer...

Actual results:

Error: Could not get children of `C:\Users\fedde\AppData\Roaming\Mozilla\Firefox\Profiles\trbz1l92.dev-edition-default\thumbnails': directory does not exist (NS_ERROR_FILE_NOT_FOUND)

Expected results:

file must have loaded correctly into firefox dev edition, but it didn't

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Firefox::Installer' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Max Christian Pohle [:/dev/max]]

Hi! Could you please clarify at which point in the installation process this message appears?

From a brief review of the code path, my understanding is that it would occur after launching the installer, proceeding through the initial steps ("Next"), and seeing the installation progress bar approaching 100%, after which the message is shown.

Can you confirm whether that matches what you’re observing?
Did you reinstall this version, or uninstall a previous version, before encountering this issue?
After the error message appeared, was Firefox Developer Edition installed successfully, or did the installation fail entirely?

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

Redirect a needinfo that is pending on an inactive user to the triage owner.
:dmcintosh, since the bug has recent activity, could you have a look please?

For more information, please visit BugBot documentation.

Comment 4

[Duncan McIntosh [:dmcintosh]]

Fedde, did you experience it breaking anything, or did this only show up post-installation? I think this is a harmless error message.

I think getting rid of it is straightforward, though, and I can reproduce it consistently by deleting %APPDATA%\Mozilla\Firefox (like it'd be for a first-time Firefox user.) I'll file a quick patch, looks like PageThumbs is newtab-related?

Comment 5

[Duncan McIntosh [:dmcintosh]]

Attachment: Bug 2021765 - Ignore the thumbnails folder not existing in PageThumbs.worker.js. r=Gijs

The case hit in the bug is the second one, I think because it's trying
to migrate from 'v0' (nonexistent) to 'v3', which involves moving the
files, but the source doesn't exist. If it doesn't exist, just don't
copy anything and remove the source.

An alternative would be checking if it exists before the migration. I
didn't do that because I implemented this first, and it would be
slightly racy if the directory existed at that check but not when the
worker got the children.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/03c38b7d65d6
https://hg.mozilla.org/integration/autoland/rev/21f7a378e95d
Ignore the thumbnails folder not existing in PageThumbs.worker.js. r=Gijs

Comment 7

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/21f7a378e95d