Provide a cleaner error message when attempting to remove a TemplateVM currently in use by other VMs

[andrewdavidwong]

Qubes OS version:

R4.0

Affected component(s):

qvm-template-postprocess?

---

$ sudo dnf remove qubes-template-whonix-gw-14 qubes-template-whonix-ws-14
Dependencies resolved.
=============================================================================================
 Package                        Arch      Version                Repository             Size
=============================================================================================
Removing:
 qubes-template-whonix-gw-14    noarch    4.0.1-201811291216     @qubes-dom0-cached    1.9 G
 qubes-template-whonix-ws-14    noarch    4.0.1-201811291216     @qubes-dom0-cached    2.3 G

Transaction Summary
=============================================================================================
Remove  2 Packages

Installed size: 4.2 G
Is this ok [y/N]: y
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
usage: qvm-template-postprocess [--verbose] [--quiet] [--help] [--really]
                                [--skip-start] [--keep-source]
                                {post-install,pre-remove} name dir
qvm-template-postprocess: error: Qube anon-whonix uses this template
error: %preun(qubes-template-whonix-ws-14-4.0.1-201811291216.noarch) scriptlet failed, exit status 2
Error in PREUN scriptlet in rpm package qubes-template-whonix-ws-14
Error in PREUN scriptlet in rpm package qubes-template-whonix-ws-14
error: qubes-template-whonix-ws-14-4.0.1-201811291216.noarch: erase failed
usage: qvm-template-postprocess [--verbose] [--quiet] [--help] [--really]
                                [--skip-start] [--keep-source]
                                {post-install,pre-remove} name dir
qvm-template-postprocess: error: Qube sys-whonix uses this template
error: %preun(qubes-template-whonix-gw-14-4.0.1-201811291216.noarch) scriptlet failed, exit status 2
Error in PREUN scriptlet in rpm package qubes-template-whonix-gw-14
Error in PREUN scriptlet in rpm package qubes-template-whonix-gw-14
qubes-template-whonix-gw-14-4.0.1-201811291216.noarch was supposed to be removed but is not!
  Verifying   : qubes-template-whonix-gw-14-4.0.1-201811291216.noarch                    1/2 
qubes-template-whonix-ws-14-4.0.1-201811291216.noarch was supposed to be removed but is not!
  Verifying   : qubes-template-whonix-ws-14-4.0.1-201811291216.noarch                    2/2 

Removed:
  qubes-template-whonix-gw-14.noarch 4.0.1-201811291216                                      
  qubes-template-whonix-ws-14.noarch 4.0.1-201811291216                                      

Complete!

In case it's relevant, these were installed by qubesctl state.sls qvm.anon-whonix.

---

Related issues:

[andrewdavidwong]

Oops, just noticed the message buried in there about extant VMs using this template. I'll convert this to a minor UX enhancement to make the error message just say that without all the other noise.

[alimirjamali]

Instead of parser.error, something better could be used here. Maybe warning messages in red color. And maybe it should warn user to use qvm-template or qvm-template-gui next time. I will work on this.

[alimirjamali]

@andrewdavidwong I just pushed a PR to fix this minor issue. Below is the output of dnf remove TEMPLATE after the patch. Please let me know if it is cleaner and acceptable. Or it should be further improved.

p.s.: I also recommend removing the ux label as this is a CLI utility issue and not a UI/UX issue.

[alimirjamali@dom0 Downloads]$ sudo dnf remove qubes-template-debian-11-minimal.noarch
Dependencies resolved.
======================================================================================================================================
 Package                                        Architecture         Version                             Repository              Size
======================================================================================================================================
Removing:
 qubes-template-debian-11-minimal               noarch               4.2.0-202307021203                  @@System               2.5 G

Transaction Summary
======================================================================================================================================
Remove  1 Package

Freed space: 2.5 G
Is this ok [y/N]: y
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                                                                              1/1 
  Running scriptlet: qubes-template-debian-11-minimal-4.2.0-202307021203.noarch                                                   1/1 
qvm-template-postprocess: ERROR!!! Qube "dummyVM1" uses this template
qvm-template-postprocess: ERROR!!! Qube "dummyVM2" uses this template
qvm-template-postprocess: WARNING!!! Do not use dnf to uninstall templates!
qvm-template-postprocess: Info: Use qvm-template(1) or Qubes Template Manager GUI to uninstall templates

error: %preun(qubes-template-debian-11-minimal-4.2.0-202307021203.noarch) scriptlet failed, exit status 1

Error in PREUN scriptlet in rpm package qubes-template-debian-11-minimal
  Verifying        : qubes-template-debian-11-minimal-4.2.0-202307021203.noarch                                                   1/1 

Failed:
  qubes-template-debian-11-minimal-4.2.0-202307021203.noarch                                                                          

Error: Transaction failed
[alimirjamali@dom0 Downloads]$ 

[andrewdavidwong]

Below is the output of dnf remove TEMPLATE after the patch. Please let me know if it is cleaner and acceptable. Or it should be further improved.

It still seems somewhat easy to miss because there are multiple lines of text both before and after, but it's better than before.

(I'm not a fan of using multiple exclamation points in a row. Urgency is not a substitute for explanation, and it seems a bit unprofessional to me.)

p.s.: I also recommend removing the ux label as this is a CLI utility issue and not a UI/UX issue.

The command-line interface is also a user interface and can have user experience problems just like any other user interface.

[alimirjamali]

It still seems somewhat easy to miss because there are multiple lines of text both before and after, but it's better than before.

The lines before and after the messages are regretfully from dnf interface and could not be suppressed and/or changed further.

(I'm not a fan of using multiple exclamation points in a row. Urgency is not a substitute for explanation, and it seems a bit unprofessional to me.)

Yes. You are right. I changed them to a sinle exclamation point.