Docs built during meson installation

[michaelgruner]

On dev-0.10 docs are built during installation and it fails on Mac OSX:

(dev-0.10 *)$ sudo ninja install
[0/1] Installing files.
Installing gst-libs/gst/r2inference/libgstinference-1.0.0.dylib to /usr/local/lib
Installing gst-libs/gst/opencv/libgstinferencebaseoverlay-1.0.0.dylib to /usr/local/lib
Installing gst/inferenceutils/libgstinferenceutils.dylib to /usr/local/lib/gstreamer-1.0
Installing ext/opencv/libgstinferenceoverlayplugin.dylib to /usr/local/lib/gstreamer-1.0
Installing ext/r2inference/libgstinference.dylib to /usr/local/lib/gstreamer-1.0
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstbackend.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstbackendsubclass.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstchildinspector.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstinferencebackends.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstinferencedebug.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstinferencemeta.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstinferencepostprocess.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstinferencepreprocess.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstinferenceclassification.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstinferenceprediction.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstncsdk.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gsttensorflow.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gsttflite.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/r2inference/gstvideoinference.h to /usr/local/include/gstreamer-1.0/gst/r2inference
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/gst-libs/gst/opencv/gstinferencebaseoverlay.h to /usr/local/include/gstreamer-1.0/gst/opencv
Installing /Users/mgruner/RidgeRun/privcam/gst-inference/build/meson-private/gstinference-1.0.pc to /usr/local/lib/pkgconfig
Running custom install script '/usr/local/bin/meson --internal gtkdoc --sourcedir=/Users/mgruner/RidgeRun/privcam/gst-inference --builddir=/Users/mgruner/RidgeRun/privcam/gst-inference/build --subdir=docs/plugins --headerdirs=/Users/mgruner/RidgeRun/privcam/gst-inference/ext/@@/Users/mgruner/RidgeRun/privcam/gst-inference/build/docs/plugins --mainfile=/Users/mgruner/RidgeRun/privcam/gst-inference/build/docs/plugins/gst-inference-plugin-docs.sgml --modulename=gst-inference-plugin-1.0 --moduleversion= --mode=auto --gtkdoc-scan=/usr/local/bin/gtkdoc-scan --gtkdoc-scangobj=/usr/local/bin/gtkdoc-scangobj --gtkdoc-mkdb=/usr/local/bin/gtkdoc-mkdb --gtkdoc-mkhtml=/usr/local/bin/gtkdoc-mkhtml --gtkdoc-fixxref=/usr/local/bin/gtkdoc-fixxref --gobjects-types-file=/Users/mgruner/RidgeRun/privcam/gst-inference/build/docs/plugins/gst-inference-plugin.types --content-files= --cc=cc --ld=cc --cflags=-I/usr/local/Cellar/libffi/3.3/include -I/usr/local/Cellar/gstreamer/1.16.2/include/gstreamer-1.0 -I/usr/local/Cellar/glib/2.64.2_1/include -I/usr/local/Cellar/glib/2.64.2_1/include/glib-2.0 -I/usr/local/Cellar/glib/2.64.2_1/lib/glib-2.0/include -I/usr/local/opt/gettext/include -I/usr/local/Cellar/pcre/8.44/include -Werror -Wmissing-declarations -Wmissing-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wformat -Wformat-nonliteral -Wformat-security -Wold-style-definition -Winit-self -Wmissing-include-dirs -Waddress -Waggregate-return -Wno-multichar -Wdeclaration-after-statement -Wvla -Wpointer-arith --ldflags=-L/usr/local/Cellar/gstreamer/1.16.2/lib -L/usr/local/Cellar/glib/2.64.2_1/lib -L/usr/local/opt/gettext/lib -lgstreamer-1.0 -lgobject-2.0 -lglib-2.0 -lintl -lgstbase-1.0'
Building documentation for gst-inference-plugin-1.0
/Users/mgruner/RidgeRun/privcam/gst-inference/ext/r2inference/gstfacenetv1.c:23: warning: Section element-gstfacenetv1 is not defined in the gst-inference-plugin-1.0-sections.txt file.
/Users/mgruner/RidgeRun/privcam/gst-inference/ext/r2inference/gstinceptionv1.c:23: warning: Section element-gstinceptionv1 is not defined in the gst-inference-plugin-1.0-sections.txt file.
/Users/mgruner/RidgeRun/privcam/gst-inference/ext/r2inference/gstinceptionv2.c:23: warning: Section element-gstinceptionv2 is not defined in the gst-inference-plugin-1.0-sections.txt file.
/Users/mgruner/RidgeRun/privcam/gst-inference/ext/r2inference/gstinceptionv3.c:23: warning: Section element-gstinceptionv4 is not defined in the gst-inference-plugin-1.0-sections.txt file.
/Users/mgruner/RidgeRun/privcam/gst-inference/ext/r2inference/gstinceptionv4.c:23: warning: Section element-gstinceptionv4 is not defined in the gst-inference-plugin-1.0-sections.txt file.
/Users/mgruner/RidgeRun/privcam/gst-inference/ext/r2inference/gstmobilenetv2.c:23: warning: Section element-gstmobilenetv2 is not defined in the gst-inference-plugin-1.0-sections.txt file.
/Users/mgruner/RidgeRun/privcam/gst-inference/ext/r2inference/gstresnet50v1.c:23: warning: Section element-gstresnet50v1 is not defined in the gst-inference-plugin-1.0-sections.txt file.
/Users/mgruner/RidgeRun/privcam/gst-inference/ext/r2inference/gsttinyyolov2.c:23: warning: Section element-gsttinyyolov2 is not defined in the gst-inference-plugin-1.0-sections.txt file.
/Users/mgruner/RidgeRun/privcam/gst-inference/ext/r2inference/gsttinyyolov3.c:23: warning: Section element-gsttinyyolov3 is not defined in the gst-inference-plugin-1.0-sections.txt file.

ERROR: Error in gtkdoc helper script:

ERROR: ['/usr/local/bin/gtkdoc-mkhtml', '--path=/Users/mgruner/RidgeRun/privcam/gst-inference/docs/plugins:/Users/mgruner/RidgeRun/privcam/gst-inference/build/docs/plugins', 'gst-inference-plugin-1.0', '..//Users/mgruner/RidgeRun/privcam/gst-inference/build/docs/plugins/gst-inference-plugin-docs.sgml'] failed with status 5
I/O error : Attempt to load network entity http://docbook.sourceforge.net/release/xsl/current/html/chunk.xsl
warning: failed to load external entity "http://docbook.sourceforge.net/release/xsl/current/html/chunk.xsl"
compilation error: file /usr/local/Cellar/gtk-doc/1.32/share/gtk-doc/data/gtk-doc.xsl line 11 element import
xsl:import : unable to load http://docbook.sourceforge.net/release/xsl/current/html/chunk.xsl

FAILED: meson-install
/usr/local/bin/meson install --no-rebuild
ninja: build stopped: subcommand failed.