[РЕШЕНО частично] MP_INPUT_BUFFER_PADDING_SIZE

Столкнулся с непонятной проблемой при сборке нескольких пакетов: Inkscape, Mplayer2, MPV. Везде выдаётся одна и та же ошибка в файле demux.c:
Вот, например, при сборке MPV:
../demux/demux.c:48:2: error: #error MP_INPUT_BUFFER_PADDING_SIZE is too small!
Build failed
-> task in 'mpv' failed (exit status 1):
{task 140107485487760: c demux.c -> demux.c.10.o}
['x86_64-pc-linux-gnu-gcc', '-O2', '-march=native', '-pipe', '-D_ISOC99_SOURCE', '-D_GNU_SOURCE', '-D_LARGEFILE_SOURCE', '-D_FILE_OFFSET_BITS=64', '-D_LARGEFILE64_SOURCE', '-std=c99', '-Wall', '-Wundef', '-Wmissing-prototypes', '-Wno-switch', '-Wno-parentheses', '-Wpointer-arith', '-Wredundant-decls', '-Wno-pointer-sign', '-Werror=implicit-function-declaration', '-Wno-error=deprecated-declarations', '-Wno-error=unused-function', '-DNO_BUILD_TIMESTAMPS', '-pthread', '-I/var/tmp/portage/media-video/mpv-0.3.10/work/mpv-0.3.10/build', '-I/var/tmp/portage/media-video/mpv-0.3.10/work/mpv-0.3.10', '-I/usr/include/quvi-0.9', '-I/usr/include/harfbuzz', '-I/usr/include/freetype2', '-I/usr/include/fribidi', '-I/usr/include/glib-2.0', '-I/usr/lib64/glib-2.0/include', '-I/usr/include/alsa', '-D_REENTRANT', '../demux/demux.c', '-c', '-o', 'demux/demux.c.10.o']

uname -a:
Linux computer 3.17.7-gentoo-computer #2 SMP Thu Dec 25 12:00:55 MSK 2014 x86_64 AMD FX(tm)-4100 Quad-Core Processor AuthenticAMD GNU/Linux

cat /etc/make.conf:
CFLAGS="-O2 -march=native -pipe"
CXXFLAGS="${CFLAGS}"
#LDFLAGS="${LDFLAGS} --as-needed"
CHOST="x86_64-pc-linux-gnu"
INPUT_DEVICES="evdev" #keyboard mouse
VIDEO_CARDS="nvidia"
USE="3dnow 3dnowext X a52 alsa cairo canberra chm cleartype cpudetection dbus
djvu drm dvdnav dxva2 egl embedded eselect faac faad fat fbcon ffmpeg
fftw fontconfig g3dvl gbm gflags gif gimp gles gles1 gles2 glew glsl
gphoto2 graphviz gtk3 hdri icu idn imagemagick imlib
introspection jbig jpeg jpeg2k kdenlive lame libcanberra libnotify
libsamplerate lightning lm_sensors lyrics lzma matroska mclib minizip mmx
mmxext mp3 mp4 mpeg2 mpeg4pt2 mpg123 mplayer multimedia netapi nsplugin
ntfs nvidia offlinehelp opencl opencv opengl osmesa pae png pnm
postscript pulseaudio quicktime rar raster raw real samba slang slideshow
sse sse2 sse2_4way sse2check sse3 sse4 sse4_1 sse4a ssse3 symlink tga
theora threads thumbnail thumbnails tiff truetype twolame type1 udf usb
vaapi vdpau wav wavpack webkit winbind xa xfce xft xosd xvid xvmc
yuv4mpeg zip -libav -bindist -bluetooth -branding -cups -hal -networkmanager
-oss -speex -wallpapers"
MAKEOPTS="-j4"
LINGUAS="ru ru_RU"
GRUB_PLATFORMS="pc multiboot coreboot"
ACCEPT_LICENSE="@BINARY-REDISTRIBUTABLE"
KDIR=/usr/src/linux
KCDIR=/root/kernel-config
PORTDIR=/usr/portage
DISTDIR="/var/cache/distfiles"
PKGDIR="/var/cache/packages"
PORTAGE_NICENESS=20
XFCE_PLUGINS="menu"
source /var/lib/layman/make.conf
GENTOO_MIRRORS="http://mirror.yandex.ru/gentoo-distfiles/"
SYNC="rsync://mirror.yandex.ru/gentoo-portage/"


Google не помог. Может быть флаг какой-то лишний. Без понятия. Пару месяцев назад всё нормально собиралось.