building academic signature on Focal Fossa(20.04 LTS) and above

Building on (X,L,K,..)ubuntu Focal

This is a dejavu of what happened before. It almost seems as if someone would be sabotaging wxWidgets in the Debian based distros.....
Unfortunately in the current (X,L,K,..)ubuntu the wxWidgets binary that ships with the distribution appears to be subtly broken. The situation is similar to what it had been in Ubuntu cosmic cuttlefish. Only the manifestation is different: Using multithreading via the wxWidgets classes is severely hampered by extreme overhead and notorious "thread congestion". If users employ the binary of wxWidgets which comes with the distro, the fastest execution is without using multithreading. Substantial use of multithreading will bring the programs down to snail pace. I don't know what these guys are doing to the binaries. Simple compilation of wxWidgets from the source with reasonable parameters will create a perfectly working binary that runs swift, flawless and makes full use of the speed improvement brought by parallelization.
The cure is the same as in the previous cases: Compile wxWidgets from the source code yourself. In order to not cause incompatibilities with the other programs that rely on the distros wxWidgets(nowadays version 3.0.4), I recomment to use the current development version of wxWidgets 3.1.x. (I never had trouble with that one so far, so the wxWidgets developers themselves are doing a good job, the packet maintainer causes the trouble.) Compiling wxWidgets is easy but may take some time.

-> 1.) Open a terminal and type "sudo apt-get update"

-> 2.) Install the developer libraries of GTK with: "sudo apt get install libgtk2.0-dev" and install automake with "sudo apt-get install automake"

-> 3.) Download the source of wxWidgets 3.1.5(or higher) and expand it into a dedicated folder of your choice, e.g., to "~/Downloads/wxWidgets"

-> 4.) Enter the directory of wxWidgets in a terminal and create a directory, e.g., with name "built_gtk"

-> 5.) Enter this directory in the terminal and type:
   "../configure" or optionally
         "../configure --disable-debug --enable-unicode --disable-shared --with-gtk" instead.

-> 6.) type  make release   (this will take a while)

-> 7.) type  "sudo make install" and then "sudo ldconfig".
This should have fixed wxWidgets by now.

It is time then to build Academic-Signature

-> 8.) Download the tar.gz archive of Academic Signature source code version 57 or higher.

-> 9.) Download my digital singature of the tar archive and verify my signature.

-> 10.) Expand the tar-archive into a dedicated folder of your choice.

-> 11.) Same procedure as usual:
Open a terminal and cd to the directory, then type "./configure". In case configure complains about a missing package (it shouldn't), supply it. Then type in the terminal "make -release". This should take a short while, produce the binary and finish without errors. You can use the resulting local copy for production use. If you prefer a system wide installation, you might type "sudo make install" and put an icon on the desktop to call the binary, which had been copied into the directory /usr/local/bin/ by this command. In this case make sure that the working directory you specify contains the needed image files "unterschrift.png" and "elliptic_m5_p4_360e_a.png", otherwise aca_sig will complain about missing images on being called. You may pick an icon of your choice from aca_sig's root directory(e.g. aca_sig_icon.png) to decorate the launcher.