The installer messed up the system. NO Icons anywhere can be displayed

[deehzee]

MY system info:
----------------------
* LM 14 Xfce
* x86 (Intel core i3 3rd gen) 8gb ram

Steps leading to the problem:
----------------------------------------
1. Started Calibre.
2. It prompted me to update, so I clicked on the link
3. The link redirected me to http://calibre-ebook.com/download_linux
4. Pasted the instruction:
sudo python -c "import sys; py3 = sys.version_info[0] > 2; u = __import__('urllib.request' if py3 else 'urllib', fromlist=1); exec(u.urlopen('http://status.calibre-ebook.com/linux_installer').read()); main(install_dir='/opt')"
5. The icons from whiskermenu disappeared
6. I rebooted.

What is the problem?
----------------------------
* AFter reboot: mdm returned the error message:
Couldn't recognize the file format:
/usr/share/mdm/themes/elegance/background.jpg

* ALL ICONS everywhere (the menu, the taskbar, the desktop, even on the buttons of chrome, thunderbird), everything disappeared and replaced by a small white box with a red cross.

* I have attached a screenshot.

Rants:
=====

PLEASE DON'T ADVISE PEOPLE TO RUN YOUR CRAPPY BINARY INSTALLER IF YOU DON'T KNOW WHAT YOU ARE DOING!!!
I DIDN'T EXPECT THIS FROM CALIBRE.
GIVE STEP BY STEP LOCAL INSTALLATION GUIDE.
DON'T MESS UP THE WHOLE SYSTEM!

[deehzee (deehzee)]

It is probably some sort of mime problem. As whenever I launch any file associated app it gives error. I also get error like:
Error loading theme icon 'image-missing' for stock: Unrecognized image file format
when opening any gtk apps.

The installer somehow corruped or over written some of my system mime info.

[Kovid Goyal (kovid)]

The calibre installer does not directly change any mime info in your
system, instead it calls xdg-mime to register its mime types.
Presumably, xdg-mime is broken on whatever crappy system you are using.

Rants
=======

PLEASE DONT USE LINUX IF YOU DONT KNOW WHAT YOU ARE DOING ESPECIALLY NOT
SOME NON_STANDARD DESKTOP ENVIRONMENT.

 status invalid

[deehzee (deehzee)]

It is not my system. It is the installer.
If the installer breaks a system that's a bug in the installer -- and it is NOT invalid.

I found out the problem was some permissions of system files were changed (by the installer obvioiusly).
I did

# chmod -R og+rX,u+rwX /usr /etc /var /lib

To fix the problem.

Now it is a problem with the installer. Alternatively, you should provide local install method that doesn't require "sudo". Poor scripting can break a system. Please check the side effects.

[deehzee (deehzee)]

And don't advise what to use to the user. Don't make a script if you are incompetent. And don't make assumptions

[deehzee (deehzee)]

More info about what happened, how to reproduce and what need to be done in the python script to avoid.

# what happened? How to reproduce.

1. Set user umask to 077
2. sudo will use this umask, unless umask_override along with new umask=0022 is defined in /etc/sudoers
3. Any file created by the python script will have default perm "-rw------- root root."

Now this should not affect existing files. Unless the script moves around existing file and save them temporarily somewhere else.

As a result the script changes the permissions of one or more system files.

[Kovid Goyal (kovid)]

Like I said, your system was broken. Specifically, you set umask to 077 and failed to modify the sudo configuration accordingly.