Bug#895503: synfig FTBFS with etl-dev 1.2.1-0.1

[Adrian Bunk]

Source: synfig
Version: 1.0.2-1
Severity: serious
Tags: buster sid

https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/synfig.html

...
/bin/bash ../../libtool  --tag=CXX   --mode=compile g++ -DHAVE_CONFIG_H   -I../.. -I../../src  -Wdate-time -D_FORTIFY_SOURCE=2 -I/usr/include -I/usr/include/glibmm-2.4 -I/usr/lib/x86_64-linux-gnu/glibmm-2.4/include -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/sigc++-2.0 -I/usr/lib/x86_64-linux-gnu/sigc++-2.0/include -pthread -I/usr/include/giomm-2.4 -I/usr/lib/x86_64-linux-gnu/giomm-2.4/include -I/usr/include/glibmm-2.4 -I/usr/lib/x86_64-linux-gnu/glibmm-2.4/include -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/sigc++-2.0 -I/usr/lib/x86_64-linux-gnu/sigc++-2.0/include -I/usr/include/libxml++-2.6 -I/usr/lib/x86_64-linux-gnu/libxml++-2.6/include -I/usr/include/libxml2 -I/usr/include/glibmm-2.4 -I/usr/lib/x86_64-linux-gnu/glibmm-2.4/include -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/sigc++-2.0 -I/usr/lib/x86_64-linux-gnu/sigc++-2.0/include -fopenmp -DMAGICKCORE_HDRI_ENABLE=0 -DMAGICKCORE_QUANTUM_DEPTH=16 -fopenmp -DMAGICKCORE_HDRI_ENABLE=0 -DMAGICKCORE_QUANTUM_DEPTH=16 -fopenmp -DMAGICKCORE_HDRI_ENABLE=0 -DMAGICKCORE_QUANTUM_DEPTH=16 -I/usr/include/x86_64-linux-gnu//ImageMagick-6 -I/usr/include/ImageMagick-6 -I/usr/include/x86_64-linux-gnu//ImageMagick-6 -I/usr/include/ImageMagick-6 -I/usr/include/x86_64-linux-gnu//ImageMagick-6 -I/usr/include/ImageMagick-6 -I/usr/include/cairo -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/pango-1.0 -I/usr/include/fribidi -I/usr/include/cairo -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -D_REENTRANT -I/usr/include/mlt++ -I/usr/include/mlt -I/usr/include/sigc++-2.0 -I/usr/lib/x86_64-linux-gnu/sigc++-2.0/include -DSYNFIG_NO_DEPRECATED -DLOCALEDIR=\"/usr/share/locale\" -DLIBDIR="\"/usr/lib/x86_64-linux-gnu\"" -DSYSCONFDIR="\"/etc/synfig\"" -fstack-protector-strong -Wformat -Werror=format-security -O2 -DNDEBUG -W -Wall -c -o libsynfig_la-canvas.lo `test -f 'canvas.cpp' || echo './'`canvas.cpp
libtool: compile:  g++ -DHAVE_CONFIG_H -I../.. -I../../src -Wdate-time -D_FORTIFY_SOURCE=2 -I/usr/include -I/usr/include/glibmm-2.4 -I/usr/lib/x86_64-linux-gnu/glibmm-2.4/include -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/sigc++-2.0 -I/usr/lib/x86_64-linux-gnu/sigc++-2.0/include -pthread -I/usr/include/giomm-2.4 -I/usr/lib/x86_64-linux-gnu/giomm-2.4/include -I/usr/include/glibmm-2.4 -I/usr/lib/x86_64-linux-gnu/glibmm-2.4/include -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/sigc++-2.0 -I/usr/lib/x86_64-linux-gnu/sigc++-2.0/include -I/usr/include/libxml++-2.6 -I/usr/lib/x86_64-linux-gnu/libxml++-2.6/include -I/usr/include/libxml2 -I/usr/include/glibmm-2.4 -I/usr/lib/x86_64-linux-gnu/glibmm-2.4/include -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/sigc++-2.0 -I/usr/lib/x86_64-linux-gnu/sigc++-2.0/include -fopenmp -DMAGICKCORE_HDRI_ENABLE=0 -DMAGICKCORE_QUANTUM_DEPTH=16 -fopenmp -DMAGICKCORE_HDRI_ENABLE=0 -DMAGICKCORE_QUANTUM_DEPTH=16 -fopenmp -DMAGICKCORE_HDRI_ENABLE=0 -DMAGICKCORE_QUANTUM_DEPTH=16 -I/usr/include/x86_64-linux-gnu//ImageMagick-6 -I/usr/include/ImageMagick-6 -I/usr/include/x86_64-linux-gnu//ImageMagick-6 -I/usr/include/ImageMagick-6 -I/usr/include/x86_64-linux-gnu//ImageMagick-6 -I/usr/include/ImageMagick-6 -I/usr/include/cairo -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/pango-1.0 -I/usr/include/fribidi -I/usr/include/cairo -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -D_REENTRANT -I/usr/include/mlt++ -I/usr/include/mlt -I/usr/include/sigc++-2.0 -I/usr/lib/x86_64-linux-gnu/sigc++-2.0/include -DSYNFIG_NO_DEPRECATED -DLOCALEDIR=\"/usr/share/locale\" -DLIBDIR=\"/usr/lib/x86_64-linux-gnu\" -DSYSCONFDIR=\"/etc/synfig\" -fstack-protector-strong -Wformat -Werror=format-security -O2 -DNDEBUG -W -Wall -c canvas.cpp  -fPIC -DPIC -o .libs/libsynfig_la-canvas.o
In file included from /usr/include/ETL/handle:41:0,
                 from layer.h:33,
                 from canvas.cpp:33:
/usr/include/ETL/_handle.h: In instantiation of 'etl::handle<T>::operator etl::handle<U>() const [with U = synfig::Layer_Composite; T = synfig::Layer]':
canvas.cpp:1370:41:   required from here
/usr/include/ETL/_handle.h:346:21: error: invalid conversion from 'etl::handle<synfig::Layer>::value_type* {aka synfig::Layer*}' to 'etl::handle<synfig::Layer_Composite>::pointer {aka synfig::Layer_Composite*}' [-fpermissive]
  { return handle<U>(obj); }
                     ^~~
/usr/include/ETL/_handle.h:198:2: note:   initializing argument 1 of 'etl::handle<T>::handle(etl::handle<T>::pointer) [with T = synfig::Layer_Composite; etl::handle<T>::pointer = synfig::Layer_Composite*]'
  handle(pointer x):obj(x)
  ^~~~~~
make[4]: *** [Makefile:1600: libsynfig_la-canvas.lo] Error 1