diff --git a/build.sh b/build.sh
index 725854c..b2c5998 100755
--- a/build.sh
+++ b/build.sh
@@ -1,7 +1,10 @@
 #!/bin/bash
 set -e
 
+SCRIPTDIR="$(dirname $(readlink -f "$0"))"
+
 abort() { local x=$1; shift; for i in "$@"; do echo >&2 "$0: abort: $i"; done; exit "$x"; }
+report() { for i in "$@"; do echo >&2 "debcargo-conf builder: $i"; done; }
 
 if [ "$(basename "$PWD")" != "build" ]; then
 	abort 1 "This script is only meant to be run from the build/ directory."
@@ -32,6 +35,8 @@
 DEBSRC=$(dpkg-parsechangelog -l $PKGNAME/debian/changelog -SSource)
 DEBDIST=$(dpkg-parsechangelog -l $PKGNAME/debian/changelog -SDistribution)
 DEB_HOST_ARCH=$(dpkg-architecture -q DEB_HOST_ARCH)
+SRCNAME="${DEBSRC}_${DEBVER}"
+BUILDNAME="${DEBSRC}_${DEBVER}_${DEB_HOST_ARCH}"
 if [ -z "$CHROOT" ] && schroot -i -c "debcargo-unstable-${DEB_HOST_ARCH}-sbuild" >/dev/null 2>&1; then
 	CHROOT="debcargo-unstable-${DEB_HOST_ARCH}-sbuild"
 fi
@@ -42,7 +47,7 @@
 	test ! -e "$dst" -o "$src" -nt "$dst"
 }
 
-if shouldbuild ${DEBSRC}_${DEBVER}.dsc "$PKGNAME/debian/changelog" ]; then
+if shouldbuild "$SRCNAME.dsc" "$PKGNAME/debian/changelog" ]; then
 	if [ "$REUSE_EXISTING_ORIG_TARBALL" = 1 ]; then
 		UPSVER="${DEBVER%-*}"
 		mv "${DEBSRC}_${UPSVER}.orig.tar.gz" "${DEBSRC}_${UPSVER}.orig.tar.gz.new"
@@ -62,7 +67,7 @@
 	( cd "$PKGNAME" && dpkg-buildpackage -d -S --no-sign )
 	# sign if not UNRELEASED
 	if echo "$DEBDIST" | grep -qv UNRELEASED-FIXME-AUTOGENERATED-DEBCARGO; then
-		debsign ${DEBSRC}_${DEBVER}_source.changes
+		debsign "${SRCNAME}_source.changes"
 	fi
 fi
 
@@ -74,8 +79,7 @@
 		apt-cache dumpavail -o APT::Default-Release=unstable | \
 		sed -e 's/Package: .*/\0\nStatus: install ok installed/g' > dpkg-dummy/status
 		if ! test -s dpkg-dummy/status; then
-			echo >&2 "couldn't generate dpkg-dummy/status, is Debian unstable in your APT sources?"
-			exit 1
+			abort 1 "couldn't generate dpkg-dummy/status, is Debian unstable in your APT sources?"
 		fi
 	fi
 	( cd "$PKGNAME" && dpkg-checkbuilddeps --admindir=../dpkg-dummy )
@@ -91,9 +95,9 @@
 	exit
 fi
 
-AUTOPKGTEST_OPTS=()
-if [ "$RUN_AUTOPKGTEST" = 1 ]; then
-	AUTOPKGTEST_OPTS=(--run-autopkgtest --autopkgtest-root-arg= --autopkgtest-opts="-- schroot ${CHROOT}")
+AUTOPKGTEST_OPTS=(--run-autopkgtest --autopkgtest-root-arg= --autopkgtest-opts="-- schroot ${CHROOT}")
+if [ "$SKIP_AUTOPKGTEST" = 1 ]; then
+	AUTOPKGTEST_OPTS=()
 fi
 
 sbuild --no-source --arch-any --arch-all \
@@ -101,10 +105,17 @@
   ${DISTRIBUTION:+-d $DISTRIBUTION} \
   ${@/#/--extra-package=} \
   "${AUTOPKGTEST_OPTS[@]}" \
-  ${DEBSRC}_${DEBVER}.dsc
-changestool ${DEBSRC}_${DEBVER}_${DEB_HOST_ARCH}.changes adddsc ${DEBSRC}_${DEBVER}.dsc
+  "$SRCNAME.dsc"
+if [ "$SKIP_AUTOPKGTEST" != 1 ]; then
+	report "analyzing autopkgtest log: $BUILDNAME.test.log"
+	# this is a bit of a hack but works OK for now, until sbuild supports %SBUILD_BUILD_DIR in --autopkgtest-opt
+	sed -ne '/autopkgtest .*: testing package .* version .*/,$p' "$BUILDNAME.build" > "$BUILDNAME.test.log"
+	"$SCRIPTDIR/dev/rust-regressions.sh" "$BUILDNAME.test.log"
+fi
+changestool "$BUILDNAME.changes" adddsc "$SRCNAME.dsc"
+report "build complete: $BUILDNAME.changes"
 
 # sign if not UNRELEASED
 if echo "$DEBDIST" | grep -qv UNRELEASED-FIXME-AUTOGENERATED-DEBCARGO; then
-	debsign ${DEBSIGN_KEYID:+-k $DEBSIGN_KEYID }--no-re-sign ${DEBSRC}_${DEBVER}_${DEB_HOST_ARCH}.changes
+	debsign ${DEBSIGN_KEYID:+-k $DEBSIGN_KEYID }--no-re-sign "$BUILDNAME.changes"
 fi
diff --git a/dev/rust-regressions.sh b/dev/rust-regressions.sh
index 2a635e4..f7d803b 100755
--- a/dev/rust-regressions.sh
+++ b/dev/rust-regressions.sh
@@ -16,7 +16,8 @@
 	local c=0
 	local url="$1"
 	local name="$(zegrep -o 'autopkgtest \[[0-9:]+\]: testing package [^[:space:]]+' "$url" | cut '-d ' -f5)"
-	if zegrep -q '^error\[E0554\]' "$url"; then
+	if zegrep -q '^error\[E0554\]' "$url" && \
+	 ! zegrep -q "^cargo-auto-test: re-running test with RUSTC_BOOTSTRAP due to E0554" "$url"; then
 		results["falsepositive_unstable"]+="$name"$'\n'
 		c=$((c+1))
 	fi
diff --git a/vars.sh.frag b/vars.sh.frag
index a4967b8..4b85fed 100644
--- a/vars.sh.frag
+++ b/vars.sh.frag
@@ -58,7 +58,7 @@
 PKGCFG="$PKGDIR/debian/debcargo.toml"
 
 mkdir -p "$(dirname $BUILDDIR)"
-cp "$PWD/build.sh" "$PWD/build/build.sh"
+ln -srf "$PWD/build.sh" "$PWD/build/build.sh"
 chmod +x "$PWD/build/build.sh"
 
 if [ -z "$CRATE" ]; then