How to Send a Script as Variable to the Meilix ISO with Travis and Meilix Generator

We wanted to add more features to Melix Generator web app to be able to customize Meilix ISO with more features so we thought of sending every customization we want to apply as a different variable and then use the scripts from Meilix Generator repo to generate ISO but that idea was bad as many variables are to be made and need to be maintained on both Heroku and Travis CI and keep growing with addition of features to web app.

So we thought of a better idea of creating a combined script with web app for each feature to be applied to ISO and send it as a variable to Travis CI.

Now another problem was how to send script as a variable after generating it as json do not support special characters inside the script. We tried escaping the special characters and the data was successfully sent to Travis CI and was shown in config but when setting that variable as an environment variable in Travis CI the whole value of variable was not taken as we had spaces in the script.

So to eliminate that problem we encoded the variable in the app as base64 and sent it to Travis CI and used it using following code.

To generate the variable from script.

with open('travis_script_1.sh','rb') as f:
    os.environ["TRAVIS_SCRIPT"] = str(base64.b64encode(f.read()))[1:]

 

For this we have to import base64 module and open the script generated in binary mode and using base64 we encode the script and using Travis CI API we send variable as script to the Travis CI to build the ISO with script in chroot we were also required to make changes in Meilix to be able to decode the script and then copy it into chroot during the ISO build.

sudo su <<EOF
echo "$TRAVIS_SCRIPT" > edit/meilix-generator.sh
mv browser.sh edit/browser.sh
EOF 

 

Using script inside chroot.

chmod +x meilix-generator.sh browser.sh
echo "$(<meilix-generator.sh)" #to test the file
./browser.sh
rm browser.sh

Resources

Base64 python documentation from docs.python.org

Base64 bash tutorial from scottlinux.com by Scott Miller

su in a script from unix.stackexchange.com answered by Ankit

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How to customize LXQT for Meilix

We had a task of customizing the LXQT (LXQt is the Qt port and the upcoming version of LXDE, the Lightweight Desktop Environment) desktop environment in Meilix for events. For example, we can use a distro at events for presentations so during presentations things like system sounds, notifications and panel can be disturbing elements of presentations so we required LXQT to be pre configured for that so the time required in configuration is not wasted or none of the presentations are disturbed.

The default configuration of LXQT are present in ~/.config/lxqt. Configuration files are in This directory is initialized automatically. The default configuration for new users is found in /etc/xdg/lxqt but we are going to use skel for this so that if there are some changes in future in the LXQT code and they do not match default settings we can always be back to default settings by deleting user side changes. Similar to LXDE. LXQt provides a GUI applications to change its settings as well.

While Openbox is the default window manager we have used in Meilix with  LXQt, you can specify a different window manager to use with LXQt via by editing ~/.config/lxqt/session.conf. To a window manager of choice. Change the following line:

window_manager=openbox

 

We have used the Openbox for Meilix.

To create a configuration for panel we can go to ~/.config/lxqt and edit the panel.conf file if it is not present we can create a file named panel.conf and add/edit the code.

[panel1]
hidable=true 

 

GIF representing auto hide of panel.

In order to configure more things like notification we can edit the ~/.config/lxqt/notification.conf.

We can change things like the placement or the size of notification or the timeout of notification in this file.

For eg:

 [General]
__userfile__=true
placement=top-left
server_decides=1
spacing=6
width=295

 

We can now place all the configurations inside the skel folder so that every new user gets the same configurations we have made.

Resources

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Updating of Linux Standard Base (lsb) and Shorten of log of Meilix Build

Updating the Linux Standard Base of the Meilix

Originally Meilix uses the Ubuntu mirror to fetch the Kernel source for the building of the Operating System. Therefore whenever a user type lsb_release -a for fetching the required information, they get the Ubuntu build info. The task is to change the config file to update the Linux Base Information from Ubuntu to Meilix.

lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 17.04
Release: 17.04
Codename: zesty

We need to patch a file in the location meilix-default-settings/etc/lsb-release which contains the information of the lsb release and this will overwrite the original configuration of Meilix.
This is how the lsb-release file looks like now:

DISTRIB_ID=Meilix
DISTRIB_RELEASE=17.04
DISTRIB_CODENAME=meilix
DISTRIB_DESCRIPTION="Meilix 17.04"

We made the required changes in the file as shown above and the output is as follows:

Shorten the log length of Meilix in Travis

We are facing issues while deployment of Meilix ISO in Travis and the error follows is ReadTimeout Error. Example log of one of fail build is:

This error gets solved automatically and the the ISO gets deployment after 1 or 2 restart of the build. But this time the error doesn’t get solved and after several attempts of restart of build, the ISO doesn’t get deployed.

Reason behind the error:

Travis is taking a lot of time to build the ISO. Travis logs are exceeding the time limit.

Proposed solution:

Reduce the time of build or shift to a new CI.
Reduce the log of the build so as to get the log within 9999 lines.

Solution Implemented

The best solution is to reduce the number of lines used in the log and this will also reduce the time of the build.
I tried concealing some command outputs by appending >/dev/null 2>&1 to some of the commands that has long outputs and adding -y to the commands like:

apt-get -qq -y --purge install file-roller unrar

References

Wiki of Linux Standard Base
Linux Foundation lsb
Ubuntu answer to reduce log

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Turning off Power Management and Blanking of Screen in Meilix

Meililx has the LXQt desktop environment which already have the lxqt-powermanagement package. We don’t need to configure the power management during an event. Every time when an ISO is booted a pop-up arrives which asks to configure power. On the one hand, the pop-ups are a disturbing element during a presentation, slide-show, etc. On the other hand, while a presentation is going on and the presenter is explaining a slide for a longer duration then there is a possibility of the screen to turn blank or screen saver to get started due to inactivity. In this post we will discuss to resolve the above two issues.

Disabling Power Management
The issue has been filed #133 to solve. We can follow two approaches to shutdown the power daemon which is responsible for starting the power-management everytime during startup.

In the beginning the issue looks as:

One is to copy the script to /etc/X11/xorg.conf.d/10-monitor.conf by editing the meilix-default-settings metapackage. 

1. [panel1]
2. alignment=-1
3. animation-duration=0
4. background-color=@Variant(\0\0\0\x43\0\xff\xff\0\0\0\0\0\0\0\0)
5. background-image=
6. desktop=0
7. font-color=@Variant(\0\0\0\x43\0\xff\xff\0\0\0\0\0\0\0\0)
8. hidable=true
9. iconSize=22
10. lineCount=1
11. lockPanel=false
12. opacity=100
13.panelSize=32
14. plugins=mainmenu, desktopswitch, quicklaunch, taskbar, tray, statusnotifier, mount, volume, clock, showdesktop
15. position=Bottom
16. show-delay=0
17. width=100
18. width-percent=true

Explanation of code:

In the Monitor section, DPMS (Desktop Power Management System) is turned off by setting the value to false
In the ServerLayout section, Blanktime, Offtime, SuspendTime, StandbyTime are set to “0”, so that they will be disabled.
Through this way we are suspending the power-management to use it feature by making changes in the script. This approach will make sure that this feature can’t be changed through the GUI, too.

And the other approach is the basic one but it’s also fulfilling the similar need. Adding a line to chroot.sh

apt-get purge lxqt-powermanagement

Both will solve the issue and the pop will not arrive at the startup of the OS.
Now LXQt desktop starts as:

Disabling Blanking of Screen in Meilix
A presenter never wants to turn his monitor blank or screensaver while presenting his presentation. Here we will edit the .profile file in the home folder to fulfill our requirement.
For get the same file in the ISO, we need to patch the file meilix-default-settings/etc/skel/.profile.
Skel folder has the property to transfer the tree inside the folder to the home folder of the new user created. For example here, the new user created will have .profile folder inside its home directory and it will apply the requested changes.

Important code which is responsible for turning the blanking of screen off:

xset s off && xset -dpms

 

Link to important pages:
Disabling Power Management – Arch Wiki
Code for turning Power Management (PR) – @meets2tarun (author)
Code for turning off blanking of screen (PR) – @meets2tarun (author)

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Configuration for Auto-hiding Panel in Meilix with LXQt desktop

In the new LXQt desktop, we can intelligently hide the panel. For that purpose, we’ll just need to patch a new file in a location under the meilix-default-settings metapackage.
Originally the file lies in the lxqt folder of the .config of the OS with the name panel.conf like .config/lxqt/panel.conf but since we have to make changes in the metapackage, we need to patch it here meilix-default-settings/etc/skel/.config/lxqt/panel.conf. Files in etc/skel/ will be put in each users’ new home folder, a folder which does not exist yet when we build the ISO.

panel.conf

1. [panel1]
2. alignment=-1
3. animation-duration=0
4. background-color=@Variant(\0\0\0\x43\0\xff\xff\0\0\0\0\0\0\0\0)
5. background-image=
6. desktop=0
7. font-color=@Variant(\0\0\0\x43\0\xff\xff\0\0\0\0\0\0\0\0)
8. hidable=true
9. iconSize=22
10. lineCount=1
11. lockPanel=false
12. opacity=100
13.panelSize=32
14. plugins=mainmenu, desktopswitch, quicklaunch, taskbar, tray, statusnotifier, mount, volume, clock, showdesktop
15. position=Bottom
16. show-delay=0
17. width=100
18. width-percent=true

In the line number 8 , hidable=true is doing all the jobs. It is the only line which hides the panel by default.

How we find this approach?
Originally LXQt panel is not hidden, they are shown by default. I first try to locate panel.conf file which will carry out the configuration for the panel. I try to find the code responsible for hiding the panel, but I can’t find that. Then I copied the panel.conf in a file and then by GUI I hide the panel and reopen the config file. Then I compare the changes between this file and the old config.panel file in which I found that the new file has a new line hidable=true. We introduced the changes in this PR.

How this approach actually work?
We are using meilix-default-settings metapackage to make the things work. We made an .config file which contains the configuration file. And the .config file is present under skel folder which gets copied under the home folder of the user. Thus ultimately we get a configuration file which will overwrite the original one to get the desired changes.

Other Uses of panel.conf
The file panel.conf could be used to customize all related settings to the LXQT panel, like its alignment, volume bar, quick launch, show desktop, etc.

References:
LXQt panel hiding
Customize LXQt desktop

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Debuilding the meilix-default-settings Metapackage

In the Meilix code repository you find a metapackage named meilix-default-settings which contains custom settings in directories as debian, etc, and user. In these directories one can make changes to make them be included in the build ISO. As Meilix runs on Debian we package our custom user settings in a Debian package to be installed along all the other software packages. The process and utility to make a Debian package is called debuild.

Directories in the meilix-default-settings:

What is debuilding?

It’s Debian slang for “making a deb package” and that stirred quite some confusion in our communications. Debuild is actually a rebuilding of the metapackage. But as to rebuild the Debian package you usually type debuild -uc -us therefore I stick to the language

Suppose someone has edited a configuration file in the metapackage according to its desires to achieve a specific result in the ISO it won’t get in unless he rebuilds the metapackage.He has not only to edit the metapackage but also to rebuild it to get the desired output in the ISO. To make the process automated, we have made a tiny script which will debuild the metapackages during each and every build, we only need to modify the metapackage.

Actually the first meilix-default-settings folder is the only metapackage and inside of it is the sub-metapackage which is responsible to get the changes applied in the ISO. To see a change in the ISO, we only need to edit the meilix-default-settings usr or etc folder in the first layer. Then, we need to debuild the metapackages.

Code-Base:

This file is present here

1. #!/bin/bash
2. rm meilix-default-settings_*                                    
3. cd meilix-default-settings                                      
4. debuild -uc -us

Let’s go through the whole code base line by line:
Line 2 deletes the previous meilix-default-settings binary packages.
Line 3 in this we changed our directory to the metapackage folder that is of our concern.
Line 4 is the most important line, it builds the whole metapackage and brings back all the binary packages and metapackages after making the desired changes.

Follow the example below to know that actually how it works:

This pull request is responsible to turn off system sounds by default in the generated ISO. Pull Requests files in which I only edited the this file and rest of the files get changes in the process of debuilding the metapackage (ignore .travis.yml file).

References:
Required files under debian directory
Debian directory guideline

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Working of Meilix Build Script

Meilix build script is divided into several parts the initial part consist of getting the build environment ready for build which includes installation of packages to build the ISO.

Iike debootstrap genisoimage p7zip-full squashfs-tools ubuntu-dev-tools.

The we have a debuild script which is ran by the build script in initially to rebuild the metapackages so that if any change is created it can be included in the build.

To make the change in metapackage like meilix-default-settings.deb we include the changes in the meilix-default-settings/ to test the meta package locally we can use the following script to build it for testing.

#!/bin/bash
rm meilix-default-settings_*                                    #removes the older meilix-default-settings packages
cd meilix-default-settings                                      #cd into the metapackage directory
debuild -uc -us                                                 #debuild the meilix-default-settings metapackage

 

After creation of packages we prepare chroot with the help of debbootstrap using ubuntu mirror for application installation after that we copy the files we created using debuild script and the files we require in the chroot.
We have a different file for working in the chroot which executes once the chroot is ready.

Now we copy the kernel from chroot to the build server /image for creation of live cd

sudo cp chroot/boot/vmlinuz-**-generic image/casper/vmlinuz sudo cp chroot/boot/initrd.img-**-generic image/casper/initrd.lz

Next step is to extract initrd for updating the uuid information for the above changes.

7z e image/casper/initrd.lz && \
  mkdir initrd_FILES/ && \
  mv initrd initrd_FILES/ && \
  cd initrd_FILES/ && \
  cpio -id < initrd && \
  cd .. && \
  cp initrd_FILES/conf/uuid.conf image/.disk/casper-uuid-generic && \

Now we pack the ISO using mkisofs but the problem here is we don’t have a boot.cat file and without that we will have errors in packing the ISO so to handle that we first create a temporary ISO to be able to extract boot.cat from it.

IMAGE_NAME=${IMAGE_NAME:-"Meilix ${release} $(date -u +%Y%m%d) - ${arch}"}
ISOFILE=meilix-${release}-$(date -u +%Y%m%d)-${arch}.iso
sudo mkisofs -r -V "$IMAGE_NAME" -cache-inodes -J -l \
  -b isolinux/isolinux.bin -c isolinux/boot.cat \
  -no-emul-boot -boot-load-size 4 -boot-info-table \
  --publisher "Meilix Packaging Team" \
  --volset "Ubuntu Linux http://www.ubuntu.com" \
  -p "${DEBFULLNAME:-$USER} <${DEBEMAIL:-on host $(hostname --fqdn)}>" \
  -A "$IMAGE_NAME" \
  -m filesystem.squashfs \
  -o ../$ISOFILE.tmp .

After getting a updated boot.cat file by mounting the temporary ISO and extracting boot.cat from it, we repeat the similar steps to create the ISO.

Chroot Script

Inside the chroot script we are going to install all the packages we require in the ISO and the metapackages we created for ISO. we can also add the custom changes we require like turning off screen dimming or setting plymouth after installing the package.

echo -ne "\033[9;0]" >> /etc/issue
setterm -blank 0 >> /etc/issue

At the end of chroot script we do the cleanup.

perl -i -nle 'print unless /^Package: language-(pack|support)/ .. /^$/;' /var/lib/apt/extended_states 
apt-get -qq clean
 rm -rf /tmp/* #rm /etc/resolv.conf 
rm meilix-default-settings_1.0_all.deb 
rm meilix-metapackage_1.0-1_all.deb 
rm systemlock_0.1-1_all.deb plymouth-meilix-logo_1.0-1_all.deb plymouth-meilix-text_1.0-1_all.deb skype-ubuntu_4.1.0.20-1_i386.deb rm meilix-imclient_*_all.deb
rm /sbin/initctl dpkg-divert --rename --remove /sbin/initctl

Resources

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Migration of LXDE Desktop of Meilix to LXQt

Meilix is originally based on LXDE and our task is to migrate Meilix desktop to LXQt. Originally LXQt is a fusion of LXDE and the Razor-Qt desktop.

What is LXDE and LXQt ?
Both are desktop environment. They are light weight with a beautiful GUI and a user-friendly touch.

Older code to install a LXDE desktop in a Debian-based environment is (source):

apt-get -q -y --purge install --no-install-recommends \
lxsession lightdm lightdm-gtk-greeter lxterminal gvfs-backends seahorse \
network-manager-gnome xorg dbus-x11 openbox ubiquity-frontend-gtk vlc \
xfce4-mixer gstreamer0.10-alsa pulseaudio pavucontrol lxpanel \
mozilla-plugin-vlc lubuntu-core jockey-gtk

In the chroot environment, the maintainer has pick up the it’s dependencies and recommend packages and listed all packages which required to install a LXDE desktop. He keeps the size as small as possible. The maintainer had hand-picked only the required packages which can run the desktop.

What we did:
We tried with several approaches. Few worked and few did not. We removed all the packages related to desktop like gnome-games, gdm and gnome-language-en since we don’t want any sort of problem conflicts in the new desktop. We had also remove all the lines mentioned above which install LXDE.

Then I simply typed the line:

apt-get -q -y install lxqt

This way we only reach to the CLI version of the OS, and we actually don’t know whether we actually have the desktop install or not.
We tried to install lighdm their by

sudo apt-get install xinit

but that was also giving errors.

We changes the line to:

apt-get -q -y install xorg sddm lxqt

And suddenly the same approach which brought to a black screen and that was a desktop and the window manager was openbox.

Then we tried to add sddm.conf to get the desktop and realized that sddm starts plasma instead of LXQt. Then we added a config file for sddm to start up LXQt by default. This file is present in the location `/etc/sddm.conf` in the meilix-default-settings metapackage with the code as:

[Autologin]
User=hotelos
Session=lxqt.desktop

But due to a bug reported here, it still starts plasma instead of LXQt. So now I have to patch a script in the location /usr/share/initramfs-tools/scripts/casper-bottom/15autologin

In last paragraph of the script it will first detect the presence of sddm, if that exists, it will assume that plasma will be default desktop and try to detect Lubuntu.desktop and QLubuntu.desktop .
So, change plasma.desktop to lxqt.desktop.

In the 15autologin changes line 84:

if [ -f /root/usr/bin/sddm ]; then
	sddm_session=lxqt.desktop
	if [ -f /root/usr/share/xsessions/Lubuntu.desktop ]; then
    	    sddm_session=Lubuntu.desktop
	fi
	if [ -f /root/usr/share/xsessions/QLubuntu.desktop ]; then
    	    sddm_session=QLubuntu.desktop
	fi
fi

Here, sddm is made to configure it must use lxqt desktop.

And this worked. Finally we get the LXQt desktop for Meilix.

Since this script along with other scripts will be packed into a small filesystem called initramfs, therefore we have to write `update-initramfs -u ` after the installation of the meilix-default-settings package.

I had made a table of the things that worked and that didn’t.

Things which do not work Things which work
1. Firstly, we removed all these lines and replace it with `apt-get -q -y install lxqt`, but this will take us to a CLI and ask to install xinit which takes us to another error. We want to straight forward go to GUI.
2. Removing of all the others desktop dependencies like gnome (here), LXDE. The way build.sh was written is that it includes suggests and recommends packages to take less space.
3. Giving less RAM to the live boot ISO which gives the error in the installation of xinit in CLI mode.
4. Removing single line and adding single line and keep on testing rather than testing on a big code. This helped us to find that where actually the issue lies.
5. Removing the rc.xml file which is responsible for openbox configuration that we don’t need in the LXQt. Screenshots are attached below.
6. Finally I booted into CLI and there I type startx which ask me to do apt-get install xinit then after that I did startx from where it takes me to the black screen.
7. I included lightdm but it’s not working and when i tried to start it using the terminal of openbox “systemctl start lightdm” , it gives the error as “failed to start lightdm.service: Unit lightdm.service not found”.
8. When I tried to install lightdm “sudo apt-get install lightdm-gtx-greeter” and we get the error pasted below.
9. Then I though to go for sddm which is a “Simple Desktop Display Manager” a replacement for lightdm.
10. Finally we make it something like this “sudo apt-get install -q -y xorg sddm lxqt”
11. sddm starts plasma (KDE) instead of LXQt for getting the desire result we need is to add /etc/sddm.conf and set its login default to lxqt.desktop
12. After screenshot of number 10, I clicked ok and logout myself to CLI and login and type startx to get the screenshot.
13. All of the things that I was doing is in the xenial version of meilix and when I tried the same in zesty. I get the following result.
14. We think there must be something why Casper uses plasma by default instead of lxqt. We can also try preventing plasma.desktop being installed in the first place.
15. Casper will set up the login when live cd is started, and the file will be changed too.
So writing to the config file (sddm.conf) actually does nothing.
16. apt install lubuntu installs lubuntu.desktop while Casper (It is actually responsible for setting up live environment, which also needs to takes care of auto login) checks for Lubuntu.desktop (noting the capital letter)
It is in the script `/usr/share/initramfs-tools/scripts/casper-bottom/15autologin`
Probably we have to patch that.
So Casper will write configs to login manager like sddm.At the time of booting the ISO into the live desktop.
The problem is, the script Casper is using, detects a different file name for LXQt.
17. We get the “15autologin file” inside chroot directory if you build the iso by yourself.
18. Then we added the line to update – initramfs (initramfs is a small filesystem that linux will mount first, which will only have basic functions, then other partitions).

Number 3

xinit error after increasing of the RAM

Number 5

Number 6

This is Openbox.

Number 8

Number 10

Number 12

Number 13.

Finally the desktop LXQt

References:
LXQt Desktop
LXDE Desktop
Switching Desktop Environment

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Creation of Icon Pack for Meilix

An icon theme is a set of icons that have common looks and feel. The user can select the icon theme that they want to use, and all apps use icons from the theme if a particular icon is not available in theme the fallback theme is used .

An icons theme is only a mapping. Given an arrangement of indexes to search for icons in and a theme name it maps from icon name and icon size to an icon filename.

Icon in Meilix are stored in /usr/share/icons/meilix.

We need to create a index.theme file which tells the LXQT desktop where the icons for a particular application or mime type are located

[Icon Theme]
Name=Meilix
DisplayDepth=32
DesktopDefault=48
DesktopSizes=16,22,32,48,64,128,256
ToolbarDefault=22
ToolbarSizes=16,22,32,48
MainToolbarDefault=22
MainToolbarSizes=16,22,32,48
SmallDefault=16
SmallSizes=16,22,32,48
PanelDefault=32
PanelSizes=16,22,32,48,64,128,256
DialogDefault=32
DialogSizes=16,22,32,48,64,128,256

#################################
#   Fallback icon theme to use  #
#################################
Inherits=oxygen

 

After defining the icon theme name and sizes we next define the fallback icon theme to use icons from in case of missing icons so we have chosen Oxygen icon theme which is very similar to Meilix icon theme to have a consistent looks and feel.

We further define the different types of icons with their locations , resolution and type.

Meilix icon theme use four different sizes 16 , 22 , 24 ,32 ,64 and two types scalable for svg icons and fixed for png icons.

[actions/32]
Size=32
Context=Actions
Type=Fixed

[actions/48]
Size=48
Context=Actions
Type=Fixed

#  Apps

[apps/16]
Size=16
Context=Applications
Type=Fixed

[apps/22]
Size=22
Context=Applications
Type=Fixed

 

Meilix Icon pack directory structure

Adding more icons to theme

To append a custom icon to Meilix icon theme xdg-icon-resource can be used. This will resize and copy the icon to /share/icons/meilix. With this method, custom emblems can also be added. Examples:

$ xdg-icon-resource install --size 64 --context --theme meilix emblems meilix-example.png --mode system # add as emblem
$ xdg-icon-resource install --size 64 --theme meilix meilix-example.png --mode system # add as normal icon

Mime type icons

file managers get definitions from /usr/share/mime/ . Calling an icon according to the definition found there and copying it to /share/icons/meilix will cause the file manager to display the custom mime type icon.

Creating a custom icon for text files (*.txt)

# grep txt /usr/share/mime/globs | egrep -o '.+\/[^:]+' | tr '/' '-'
application-x-kate ;# rename your icon according to this output
xdg-icon-resource install --size 64 --context mimetypes --theme meilix application-x-kate.png --mode system

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