diff --git a/Makefile b/Makefile
index aaf4d90..f0ab803 100644
--- a/Makefile
+++ b/Makefile
@@ -91,11 +91,11 @@ endif
 LIBQUARK_DEPS:= $(filter-out manpages.h, $(LIBQUARK_DEPS))
 LIBQUARK_SRCS:=			\
 	bpf_queue.c		\
-	btf.c			\
 	btfhub.c		\
 	compat.c		\
 	kprobe_queue.c		\
 	quark.c			\
+	qbtf.c			\
 	qutil.c
 LIBQUARK_OBJS:= $(patsubst %.c,%.o,$(LIBQUARK_SRCS))
 LIBQUARK_STATIC:= libquark.a
diff --git a/krun-fedora.sh b/krun-fedora.sh
index 88f6159..1427a19 100755
--- a/krun-fedora.sh
+++ b/krun-fedora.sh
@@ -19,7 +19,6 @@ function usage
 	echo "  command...      Command to run in guest"
 	echo
 	echo "Examples:"
-	echo "  $SCRIPT initramfs.gz 40 /bin/bash"
 	echo "  $SCRIPT -v initramfs.gz rawhide quark-test -vvv"
 	exit 1
 }
@@ -45,7 +44,7 @@ shift 2
 [[ -f ./krun.sh ]] || die "Required launcher ./krun.sh is missing"
 
 case $FEDORAVER in
-2?|3?)		URL="https://archives.fedoraproject.org/pub/archive/fedora/linux/updates/$FEDORAVER/Everything/x86_64/Packages/k";;
+2?|3?|40)	URL="https://archives.fedoraproject.org/pub/archive/fedora/linux/updates/$FEDORAVER/Everything/x86_64/Packages/k";;
 43|rawhide)	URL="https://ftp.fau.de/fedora/linux/development/$FEDORAVER/Everything/x86_64/os/Packages/k";;
 4?)		URL="https://ftp.fau.de/fedora/linux/updates/$FEDORAVER/Everything/x86_64/Packages/k";;
 *)		die "Unsupported Fedora version: $FEDORAVER";;
@@ -59,7 +58,7 @@ cleanup()	{ [[ -d "$TMPDIR" ]] && rm -rf "$TMPDIR"; }
 trap cleanup EXIT
 
 log "Fetching package list from $URL"
-RPMURL=$(lynx -dump -listonly "$URL"|grep kernel-core)
+RPMURL=$(lynx -dump -listonly "$URL"|grep kernel-core) || die "Can't fetch package list"
 RPMURL=${RPMURL##* }
 RPM=$(basename "$RPMURL")
 VMLINUZ=${RPM##kernel-core-}
diff --git a/krun-rhel.sh b/krun-rhel.sh
index 3d3c61e..6f160d7 100755
--- a/krun-rhel.sh
+++ b/krun-rhel.sh
@@ -19,7 +19,6 @@ function usage
 	echo "  command...   Command to run in guest"
 	echo
 	echo "Examples:"
-	echo "  $SCRIPT initramfs.gz 9 /bin/bash"
 	echo "  $SCRIPT -v initramfs.gz 8.4 quark-test -vvv"
 	exit 1
 }
@@ -60,7 +59,7 @@ cleanup()	{ [[ -d "$TMPDIR" ]] && rm -rf "$TMPDIR"; }
 trap cleanup EXIT
 
 log "Fetching package list from $URL"
-RPMURL=$(lynx -dump -listonly "$URL"|grep kernel-core)
+RPMURL=$(lynx -dump -listonly "$URL"|grep kernel-core) || die "Can't fetch package list"
 RPMURL=${RPMURL##* }
 RPM=$(basename "$RPMURL")
 VMLINUZ=${RPM##kernel-core-}
diff --git a/krun-ubuntu.sh b/krun-ubuntu.sh
index d5552d3..a7fb4e1 100755
--- a/krun-ubuntu.sh
+++ b/krun-ubuntu.sh
@@ -30,7 +30,6 @@ usage() {
 	echo "  command...      Command to run in guest"
 	echo
 	echo "Examples:"
-	echo "  $SCRIPT initramfs.gz 22.04 /bin/bash"
 	echo "  $SCRIPT -v initramfs.gz 24.04 quark-test -vvv"
 	exit 1
 }
diff --git a/btf.c b/qbtf.c
similarity index 100%
rename from btf.c
rename to qbtf.c
diff --git a/quark.h b/quark.h
index 0d5b1fc..9964cd1 100644
--- a/quark.h
+++ b/quark.h
@@ -90,14 +90,6 @@ struct bpf_probes	*quark_get_bpf_probes(struct quark_queue *);
 /* kprobe_queue.c */
 int	kprobe_queue_open(struct quark_queue *);
 
-/* XXX terrible name XXX */
-struct args {
-	char		*buf;
-	size_t		 buf_len;
-	int		 argc;
-	const char	*argv[];
-};
-
 /* qutil.c */
 struct qstr {
 	char	*p;