dev: make sure clobber removes all autoconf-generated files

and make sure autoconf is installed in the basic ubuntu container in CI

Author: flavorjones

.github/workflows/ci.yml

@@ -46,6 +46,7 @@ jobs:
       - uses: actions/checkout@v1 # v1 because of https://github.com/actions/checkout/issues/334
         with:
           submodules: true
+      - run: apt install autoconf
       - run: bundle install --local || bundle install
       - run: bundle exec rake compile -- --${{matrix.sys}}-system-libraries
       - run: bundle exec rake test

rakelib/gumbo.rake

@@ -35,9 +35,11 @@ namespace "gumbo" do
   CLOBBER.add(gtest_pkg)
   CLOBBER.add(gumbotest_configure)
   CLOBBER.add("gumbo-parser/Makefile.in")
-  CLOBBER.add("gumbo-parser/configure")
   CLOBBER.add("gumbo-parser/src/Makefile.in")
   CLOBBER.add("gumbo-parser/test/Makefile.in")
+  CLOBBER.add("gumbo-parser/build-aux/*")
+  CLOBBER.add("gumbo-parser/autom4te.cache")
+  CLOBBER.add("gumbo-parser/aclocal.m4")
 end
 
 desc "Run the gumbo parser test suite"