The symbols file for this package contains the invalid placeholder #PACKAGE# in the Build-Depends-Package field. It will be replaced with the wrong value during the build process. There is currently no placeholder that works. The development package for your shared library must be stated explicitly.
Please do not use the placeholder #PACKAGE#.
The field should specify the name of the -dev package associated with the library. It is used by dpkg-shlibdeps(1) to make sure that the generated installation dependency is at least as strict as the build dependency.
Refer to Debian Policy Manual section 22.214.171.124 (The
symbols File Format), the deb-symbols(5) manual page, the dpkg-shlibdeps(1) manual page, https://www.debian.org/doc/manuals/maint-guide/advanced.en.html#librarysymbols, and https://bugs.debian.org/944047 for details.