I would thus propose simply dropping the build-dependency, a debdiff doing that is attached, I may or may not NMU it later.
I have gone ahead with the NMU, final debdiff is attatched.
diff -Nru xscorch-0.2.1/debian/changelog xscorch-0.2.1/debian/changelog --- xscorch-0.2.1/debian/changelog 2020-09-12 08:10:17.000000000 +0100 +++ xscorch-0.2.1/debian/changelog 2021-02-18 20:50:52.000000000 +0000 @@ -1,3 +1,11 @@ +xscorch (0.2.1-1+nmu6) unstable; urgency=medium + + * Non-maintainer upload. + * Remove build-dependency on libreadline-gplv2-dev + (Closes: 982559) + + -- Peter Michael Green <plugw...@debian.org> Thu, 18 Feb 2021 20:50:52 +0000 + xscorch (0.2.1-1+nmu5) unstable; urgency=medium * Non-maintainer upload. diff -Nru xscorch-0.2.1/debian/control xscorch-0.2.1/debian/control --- xscorch-0.2.1/debian/control 2020-07-02 15:45:01.000000000 +0100 +++ xscorch-0.2.1/debian/control 2021-02-18 20:48:27.000000000 +0000 @@ -4,7 +4,7 @@ Homepage: http://www.xscorch.org/ Maintainer: Jacob Luna Lundberg <ja...@gnifty.net> Standards-Version: 3.9.2 -Build-Depends: debhelper (>= 7), groff, libglib2.0-dev, libgtk2.0-dev (>= 2.20), libmikmod-dev, libreadline-gplv2-dev | libreadline5-dev, libx11-dev, libxext-dev, libxi-dev, autotools-dev +Build-Depends: debhelper (>= 7), groff, libglib2.0-dev, libgtk2.0-dev (>= 2.20), libmikmod-dev, libx11-dev, libxext-dev, libxi-dev, autotools-dev Package: xscorch Architecture: any