--- configure.orig	2020-08-23 11:59:54 UTC
+++ configure
@@ -22134,7 +22134,7 @@ $as_echo_n "checking whether pthread_t is integer... "
 int
 main ()
 {
-pthread_t k; k * 1;
+pthread_t k; k = (pthread_t) -1;
   ;
   return 0;
 }
@@ -26279,7 +26279,7 @@ for be in ${BACKENDS}; do
     ;;
 
     v4l)
-    if test "${have_linux_ioctl_defines}" != "yes" \
+    if test "${have_libv4l1}" != "yes" \
       || test "${have_libv4l1}" != "yes"; then
       echo "*** $be backend requires v4l libraries - $DISABLE_MSG"
       backend_supported="no"
@@ -26482,7 +26482,7 @@ for be in ${BACKENDS}; do
     ;;
 
     v4l)
-    if test "${have_linux_ioctl_defines}" != "yes" \
+    if test "${have_libv4l1}" != "yes" \
       || test "${have_libv4l1}" != "yes"; then
       echo "*** $be backend requires v4l libraries - $DISABLE_MSG"
       backend_supported="no"