Moreover there's some lintian proposed fixes that may be worth looking into:
P: haproxy source: unneeded-build-dep-on-quilt
I: haproxy source: quilt-patch-missing-description bashism
W: haproxy source: out-of-date-standards-version 3.9.1 (current is 3.9.2)
P: haproxy: example-shell-script-fails-syntax-check usr/share/doc/haproxy/examples/build.cfg
P: haproxy: example-shell-script-fails-syntax-check usr/share/doc/haproxy/examples/haproxy-1.1.21-flx.1.pkg
P: haproxy: example-shell-script-fails-syntax-check usr/share/doc/haproxy/examples/init.haproxy
I: haproxy: unused-override example-shell-script-fails-syntax-check ./usr/share/doc/haproxy/examples/build.cfg
I: haproxy: unused-override example-shell-script-fails-syntax-check ./usr/share/doc/haproxy/examples/haproxy-1.1.21-flx.1.pkg
I: haproxy: unused-override example-shell-script-fails-syntax-check ./usr/share/doc/haproxy/examples/init.haproxy