All that was for 💩

_set_cfg_file sub in Astro::Catalog::Query::SkyCat searches for configuration file in equivalent of %ENV|$HOME|dirname($^X)/../etc (there is nice comment there about the last one).

No message is produced by App::SourcePlot to set up a catalog file in HOME on the first run. On subsequent runs, using the Tk widget to use "default" catalog results on console ...

Tk::Error: Unable to read catalog since no file specified and no defau
+lt known. at /some/dir/perl/lib/perl5/Astro/Catalog.pm line 842.
 Tk callback for .toplevel1.frame1.menubutton.menu
 Tk::__ANON__ at /some/dir/perl/lib/perl5/x86_64-linux-thread-multi/Tk
+.pm line 251
 Tk::Menu::Invoke at /some/dir/perl/lib/perl5/x86_64-linux-thread-mult
+i/Tk/Menu.pm line 532
 <ButtonRelease>
 (command bound to event)
[download]

👍

Yes, I can _NOW_ shove the configuration files in HOME only after trying to debug the issue of not being able to specify a path for etc directory of *::Catalog.