Default spice4qucs working directory path set to /spice4qucs

[bladane]

Installed qucs-s 0.0.23 for ubuntu20.04 (followed procedure from the site: [https://ra3xdh.github.io/#docs] ).

It also installed ngspice-31 that I checked with simple *.cir example and it is working. So Ngspice is working.

Then I opened Qucs 0.0.23 and created an example of RC schematic from tutorial (prior to this set ngspice as default simulator and directed to Ngspice executable location: /usr/bin/ngspice) but when tried to simulate it is showing:

• popup window Simulate with external simulator with message in Simulation console - Ngspice started and
• new popup window with message Failed to start simulator.
• And when Failed to start simulator popup is closed it writes inside Simulation console new message - Ngspice error...

Any recommendation how to debug this problem.

[ra3xdh]

This may be related to #85 Please send me your qucs-s.conf file. I cannot reproduce this issue on my clean Ubunutu20.04 installation. It seems that the path for netlist file somehow set is unwriteable.

[bladane]

here is the content of qucs-s.conf (renamed to txt):
qucs_s.conf.txt
Thnx!

[ra3xdh]

Yes, my suspicions were correct. The working directory is not writeable. Please also send me screenshot from the Simulation->Select default simulator menu. I am interested what is this setting:

[bladane]

Here is the screenshot -

[bladane]

Fixed it by changing the directory to store netlist and simulator output to my home dir (/home/user/.qucs). Now it is working!
Thank you one again!

[ra3xdh]

As a workaround you may to set "Directory to store netlist ..." as the writeable path. Usually it should be $HOME/.qucs/spice4qucs/. I will check why it may be not set correctly automatically.

[bladane]

Done as per your suggestion.

[ra3xdh]

Yes, I can reproduce an issue now. The Qucs-S may set the working directory as an unwriteable path. It's strange that it was not discovered before. I will provide a fix soon.

[ra3xdh]

I made more investigations on this. The issue can take place if the directory $HOME/.qucs doesn't exist. The QDir::absolutePath() returns an empty string in such case (main.cpp line 147). This also explains why this issue was discovered only recently. The most of Qucs-S users had also Qucs installed and .qucs directory was already presented on the first application start.

[bladane]

I had qucs but it was installed with snap (and in snap directory). And that is not visible to qucs-s.

[ra3xdh]

Fixed by 6d78f16 on master branch. The fix will be available in 0.0.24 release.