[Reproducible-builds] Bug#790911: FTBFS: src/sna/sna_driver.c: error: implicit declaration of function 'fstat'

[Chris West (Faux)]

Source: xserver-xorg-video-intel
Version: 2:2.99.917-1
Severity: serious
Tags: sid
Justification: fails to build from source (but built successfully in the past)
User: reproducible-builds at lists.alioth.debian.org
Usertags: ftbfs

Dear Maintainer,

The package fails to build:
.../../../src/sna/sna_driver.c: In function 'sna_handle_uevents':
.../../../src/sna/sna_driver.c:799:2: error: implicit declaration of function 'fstat' [-Werror=implicit-function-declaration]
  if (fstat(sna->kgem.fd, &s) || memcmp(&s.st_rdev, &udev_devnum, sizeof (dev_t))) {
  ^
.../../../src/sna/sna_driver.c:799:2: warning: nested extern declaration of 'fstat' [-Wnested-externs]

Probably the same cause / fix as https://bugs.debian.org/790631 , but I'm guessing "missing header".

Full build log:
https://reproducible.debian.net/rb-pkg/unstable/amd64/xserver-xorg-video-intel.html

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 3.19.0-21-generic (SMP w/8 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)