Space in filename Rclone UI.png causes error when rebuilding icon cache. Linux Mint, possibly others.

[Eternal9100]

When installing or uninstalling with a package manager on Mint the icon cache is updated. From the CLI you get the error message:

gtk-update-icon-cache /usr/share/icons/hicolor gtk-update-icon-cache: The generated cache was invalid.

Researching the most common cause for this error is a space in the icon file name. A search in this folder shows there to be three such filenames:

/usr/share/icons/hicolor/128x128/apps/Rclone UI.png
/usr/share/icons/hicolor/256x256@2/apps/Rclone UI.png
/usr/share/icons/hicolor/32x32/apps/Rclone UI.png'

Changing these to Rclone-UI.png and then rebuilding the cache with:

sudo gtk-update-icon-cache /usr/share/icons/hicolor results in the output:

gtk-update-icon-cache: Cache file created successfully.

The icon file has to be updated for any desktop or menu .desktop files with Rclone-UI in the search box. (In Mint). I assume this will have the same effect in all debian and ubuntu gtk desktops. Suggested fix, on upgrade remove icon files with a space and replace with a filename with no space.

[FTCHD]

This is a good find, and potentially the right solution but I need to make sure.

I remember having issues with the icon on flatpak.

[Eternal9100]

Don't know about flatpak, and I think its's a gtk thing so may not be problem for KDE desktops:

meat@box:~/Downloads$ sudo apt install ./Rclone.UI_amd64.deb
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Note, selecting 'rclone-ui' instead of './Rclone.UI_amd64.deb'
The following packages will be upgraded:
rclone-ui
1 to upgrade, 0 to newly install, 0 to remove and 0 not to upgrade.
Need to get 0 B/18.4 MB of archives.
After this operation, 5,120 B of additional disk space will be used.
Get:1 /home/meat/Downloads/Rclone.UI_amd64.deb rclone-ui amd64 3.0.2 [18.4 MB]
(Reading database ... 606952 files and directories currently installed.)
Preparing to unpack .../Downloads/Rclone.UI_amd64.deb ...
Unpacking rclone-ui (3.0.2) over (3.0.1) ...
Setting up rclone-ui (3.0.2) ...
Processing triggers for desktop-file-utils (0.27-2build1) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...
gtk-update-icon-cache: The generated cache was invalid.
WARNING: icon cache generation failed
Processing triggers for gnome-menus (3.36.0-1.1ubuntu3) ...
Processing triggers for mate-menus (1.26.1+mint1) ...
Processing triggers for mailcap (3.70+nmu1ubuntu1) ...

run the icon cache rebuild again:

meat@box:~/Downloads$ sudo update-icon-caches /usr/share/icons/*
[sudo] password for meat:
gtk-update-icon-cache: The generated cache was invalid.
WARNING: icon cache generation failed for /usr/share/icons/hicolor

remove these with space:

then run again:

meat@box:/Downloads$ sudo update-icon-caches /usr/share/icons/*
meat@box:/Downloads$

I am pretty confident it is the cause of this problem. The message will appear for any package installed or modified from CLI until the offending file names are changed or deleted. It makes upgrades a bit of chore unless I do a shell script to delete three icon files? If you resolve your flatpak issue as well, what's not to like?

[alexrhyshurn]

I am having the same issue on Raspberry Pi OS 64bit Trixie as below errors:

Processing triggers for hicolor-icon-theme (0.18-2) ...
gtk-update-icon-cache: The generated cache was invalid.
WARNING: icon cache generation failed
Processing triggers for mailcap (3.74) ...
Errors were encountered while processing:
 rclone-ui

[W4JEW]

As indicated by @Eternal9100... Renaming the files in the respective directories from Rclone UI.png to Rclone_UI.png allowed me to run the following, and it completed successfully:

gtk-update-icon-cache: Cache file created successfully.

sudo gtk-update-icon-cache /usr/share/icons/hicolor

But the icon on the apps menu broke, and Rclone UI won't launch.

I should add that I installed Rclone UI using the deb package from https://rcloneui.com, but I don't think that's related to the GTK cache issue.

[FTCHD]

Please download the repo, apply the fix locally, run it to confirm it works then open a Pull Request.

You need node and rust installed. See more info here #134 (comment)

Merged PRs receive a lifetime license!

[Eternal9100]

@W4JEW I just update the icon attached to the menu entry but I am surprised you can invoke RCUI. You don't say what DE you are using. In general, I think spaces in filenames for icons are a longstanding bug for GTK based DE's and spaces in binary names are a not a good idea in Linux (or Windows).