Full debug is enabled
error: argument 1 null where non-null expected


$ git shortlog -1
Fabian (1):
      Merge branch 'master' of ssh://git.xfce.org/panel-plugins/xfce4-sensors-plugin

$ ./autogen.sh --prefix=/usr --enable-debug
...
===============================================================
Build Configuration
===============================================================

The following sensor interfaces will be built into the plugin:
*  hddtemp: /usr/sbin/hddtemp (Make sure it is user-executable with UID bit set 
                      and user member of the respective group)
*  libsensors
*  /proc/acpi
*  /sys/class/power_supply

Support for libnotify will be built in.

Support for libnotify >= 0.7 will be built in.

Full debug is enabled

===============================================================
Now type "make" to compile.
$ make
...
acpi.c: In function ‘read_thermal_zone’:
acpi.c:111:13: error: argument 1 null where non-null expected [-Werror=nonnull]
             closedir (ptr_directory);
             ^~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/glib-2.0/glib/gdir.h:32:0,
                 from /usr/include/glib-2.0/glib.h:45,
                 from ../include/acpi.h:37,
                 from acpi.c:27:
/usr/include/dirent.h:149:12: note: in a call to function ‘closedir’ declared here
 extern int closedir (DIR *__dirp) __nonnull ((1));
            ^~~~~~~~
cc1: all warnings being treated as errors
...


$ grep -B1 -A6 'Close.*DIRP' /usr/include/dirent.h

/* Close the directory stream DIRP.
   Return 0 if successful, -1 if not.

   This function is a possible cancellation point and therefore not
   marked with __THROW.  */
extern int closedir (DIR *__dirp) __nonnull ((1));


$ rpm --query --file /usr/include/dirent.h
glibc-headers-2.25-1.fc26.x86_64