[GNC] Guile missing -- but not missing

[Stephen M. Butler]

> Did you install the appropriate -dev packages?

Apparently not the -dev ones.
> Why not run the apt command to install all the build dependencies?  I
> think something like apt build-dep gnucash?
sudo apt build-dep gnucash
Installing:
   debhelper  dh-python  guile-3.0-dev  imagemagick imagemagick-7.q16  
libgwengui-gtk3-dev  libxml2-utils  locales-all texinfo

Installing dependencies:
   autopoint      dh-strip-nondeterminism  libdebhelper-perl       
  libgmp-dev      libreadline-dev         tex-common
   debugedit      dwz libfile-stripnondeterminism-perl  libgmpxx4ldbl 
  libtext-unidecode-perl  texinfo-lib
   dh-autoreconf  intltool-debian          libgc-dev       
  libncurses-dev  po-debconf

Suggested packages:
   dh-make            imagemagick-7-doc  gimp      html2ps 
  texlive-base-bin  libmpfr-dev       texlive-latex-base
   flit               autotrace          gnuplot   libwmf-bin transfig  
         ncurses-doc       texlive-plain-generic
   python3-build      curl               grads     mplayer  libraw-bin  
       readline-doc      texlive-fonts-recommended
   python3-installer  enscript           graphviz  povray gmp-doc        
    libmail-box-perl
   python3-wheel      ffmpeg             hp2xx     radiance 
libgmp10-doc      texlive-base

Recommended packages:
   netpbm  libarchive-cpio-perl  libmail-sendmail-perl

Summary:
   Upgrading: 0, Installing: 26, Removing: 0, Not Upgrading: 4
   Download size: 17.6 MB
   Space needed: 266 MB / 194 GB available