I installed (actually upgraded from 42.2 via 42.3) Leap 15.0 (x86_64) this weekend, then installed gnucash-3.0-lp150.1.12. When running /usr/bin/gnucash it complained about missing libraries:
% ldd /usr/bin/gnucash | grep found
libwebkitgtk-1.0.so.0 => not found
libjavascriptcoregtk-1.0.so.0 => not found
I looked at the RPM dependencies, and it appeared that the required RPMs were installed, so I made the following symlinks to see if any forward progress would be made:
cd /usr/lib64
ln -s libwebkit2gtk-4.0.so libwebkitgtk-1.0.so.0
ln -s libjavascriptcoregtk-4.0.so libjavascriptcoregtk-1.0.so.0
Then tried running it and saw this error:
% /usr/bin/gnucash
/usr/bin/gnucash: symbol lookup error: /usr/lib64/gnucash/libgncmod-app-utils.so: undefined symbol: gnc_build_userdata_path
Interestingly if I try to build Gnucash 3.1 from source it also complains about gnc_build_userdata_path during the make and the make fails.