Attached patch re-enables the plugins and builds fine for me within sbuild on sid (and works fine for MQTT on buster).
J. -- Professional Geek + recovering Law Student https://www.linkedin.com/in/noodles 101 things you can't have too much of : 51 - News.
diff -Nru collectd-5.8.1/debian/changelog collectd-5.8.1/debian/changelog --- collectd-5.8.1/debian/changelog 2018-12-25 11:08:23.000000000 +0000 +++ collectd-5.8.1/debian/changelog 2019-04-03 21:56:47.000000000 +0100 @@ -1,3 +1,10 @@ +collectd (5.8.1-1.3) unstable; urgency=medium + + * Non-maintainer upload. + * Re-enable mqtt + varnish plugins. (Closes: #924337) + + -- Jonathan McDowell <nood...@earth.li> Wed, 03 Apr 2019 21:56:47 +0100 + collectd (5.8.1-1.2) unstable; urgency=medium * Non-maintainer upload. diff -Nru collectd-5.8.1/debian/control collectd-5.8.1/debian/control --- collectd-5.8.1/debian/control 2018-12-19 14:51:04.000000000 +0000 +++ collectd-5.8.1/debian/control 2019-04-03 21:55:59.000000000 +0100 @@ -32,6 +32,7 @@ libmicrohttpd-dev, libmodbus-dev, libmongoc-dev, + libmosquitto-dev, libmnl-dev [linux-any], libnotify-dev, libopenipmi-dev, @@ -54,7 +55,7 @@ libtokyotyrant-dev [linux-any], libudev-dev [linux-any], libupsclient-dev | libupsclient1-dev, -# libvarnishapi-dev, + libvarnishapi-dev, libvirt-dev (>= 0.4.0-6) [linux-any], libxen-dev [amd64 arm64 armhf i386], libxml2-dev, diff -Nru collectd-5.8.1/debian/rules collectd-5.8.1/debian/rules --- collectd-5.8.1/debian/rules 2018-12-19 14:51:28.000000000 +0000 +++ collectd-5.8.1/debian/rules 2019-04-03 21:56:12.000000000 +0100 @@ -88,14 +88,6 @@ # Cf. https://github.com/collectd/collectd/issues/1574 confflags += --disable-sigrok -# temporarily disable varnish plugin, as #879471 blocks collectd from -# migrating to testing. -confflags += --disable-varnish - -# temporarily disable mqtt plugin, as #911265, #911266 blocks collectd from -# migrating to testing. -confflags += --disable-mqtt - # disable lvm plugin, liblvm2app is deprecated upstream, #915692 # Cf. https://github.com/collectd/collectd/issues/2647 confflags += --disable-lvm
