Work around ubuntu build environment

TODO:
- dont just ignore missing info, have something to fill it in even when
  the require arch binaries are missing

.github/workflows/tests.yml

@@ -408,11 +408,9 @@ jobs:
 
       - name: Install packages needed for build
         run: |
-          sudo dpkg --add-architecture ${{ matrix.arch }}
           sudo apt-get update
           sudo apt-get install debhelper build-essential \
             devscripts \
-            libc6:${{ matrix.arch }} \
             crossbuild-essential-${{ matrix.arch }}
 
       - name: Configure

packages/debian/debian/rules

@@ -50,7 +50,7 @@ binary-arch: build install
 	cp -r ../etc debian/n2n
 	find debian/n2n -name "*.in" -exec /bin/rm {} ';'
 	find debian/n2n -name "*~" -exec /bin/rm {} ';'
-	dh_shlibdeps
+	dh_shlibdeps --dpkg-shlibdeps-params=--ignore-missing-info
 	dh_link
 	dh_gencontrol
 	dh_md5sums