--- cabal-install-2.4.0.0.old/bootstrap.sh
+++ cabal-install-2.4.0.0/bootstrap.sh
@@ -346,7 +346,10 @@
   rm -rf "${PKG}-${VER}.tar" "${PKG}-${VER}"
   ${GZIP_PROGRAM} -d < "${PKG}-${VER}.tar.gz" | ${TAR} -xf -
   [ -d "${PKG}-${VER}" ] || die "Failed to unpack ${PKG}-${VER}.tar.gz"
-  cp "${PKG}.cabal.hackage" "${PKG}-${VER}/${PKG}.cabal"
+  PCHA="${PKG}.cabal.hackage"
+  if [ -f $PCHA ]; then
+       cp $PCHA "${PKG}-${VER}/${PKG}.cabal"
+  fi
 }
 
 install_pkg () {