[GNC] debian seems be missing file in amd64 gnucash package

[John Griessen]

I tried using apt install:

sudo apt install -t sid libboost-regex1.62.0
sudo apt install -t sid gnucash gnucash-common gnucash-docs python3-gnucash

and I just get this error:

gnucash: symbol lookup error: /usr/lib/x86_64-linux-gnu/gnucash/gnucash/libgncmod-app-utils.so: undefined symbol: 
gnc_build_userdata_path

and I find no file /usr/lib/x86_64-linux-gnu/gnucash/gnucash/libgncmod-app-utils.so
and that debian package gnucash for amd64
https://packages.debian.org/jessie/amd64/gnucash/filelist
is supposed to contain this file:
/usr/lib/x86_64-linux-gnu/gnucash/gnucash/libgncmod-app-utils.so

so next I am trying flatpak, but wonder if
this is a clue to why I can't get gnucash running on debian yet...

Any ideas?

my /etc/apt/sources.list file has:

deb http://deb.debian.org/debian buster main non-free contrib
deb-src http://deb.debian.org/debian buster main non-free contrib

lines in it among others.

The buster repo is coming from here during update:

Hit:3 http://cdn-fastly.deb.debian.org/debian buster InRelease 

Hit:7 https://s3-us-west-2.amazonaws.com/brave-apt buster InRelease

Anyone?