How can make the controler configuration window show in pcsxr?

Solution 1:

Ubuntu 18.04 shipped with many broken packages, and pcsxr is one of them. Fortunately, pcsxr is among the few packages that can be easily fixed. The solution is to install the functioning input plugin from the 16.04 version of pcsxr. (All credit goes to josefien for figuring this out)

1. Install pcsxr normally: sudo apt install pcsxr
2. Download the 16.04 version of pcsxr: https://packages.ubuntu.com/xenial/pcsxr (most likely the amd64 version; uname -a will give display your architecture, if you see x86_64 then pick amd64 in the download)
3. Extract the deb archive (right click -> extract here). You will find a file data.zip that needs to be extracted as well.
4. From the data file, you'll need to copy three files. Two of the three will replace preexisting files. In the terminal, go to the extracted data file and copy the folling files:
   1. sudo cp usr/lib/x86_64-linux-gnu/psemu/cfgDFInput /usr/lib/x86_64-linux-gnu/psemu/cfgDFInput
   2. sudo cp /usr/lib/x86_64-linux-gnu/psemu/libDFInput.so -> /usr/lib/x86_64-linux-gnu/psemu/libDFInput.so
   3. sudo cp /usr/share/psemu/dfinput.glade2 /usr/share/psemu/dfinput.glade2
5. Since we're using glade again, you'll also need to install or it wont work: sudo apt install libglade2-0
6. This is not strictly related to this question, but the pcsxr package is still broken but in another way: You need to set Cpu = 1 in ~/.pcsxr/pcsxr.cfg or pcsxr will crash.

With that, you're all set. The configuration window should appear normally and your controller should be detected and ready for configuration.