Compilation error when using -DCMAKE_CXX_COMPILER

[stoecker]

LibreSprite version

1.0

Describe the bug

libduktape.a is compiled with a different compiler than the rest of the software:

...
BUILD/LibreSprite-1.0/build/src/script && /usr/bin/cc -DHAVE_CONFIG_H -DNDEBUG -DSCRIPT_ENGINE_LUA=1 -DUSE_SDL2_BACKEND -I/usr/include/libpng16 -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/lua5.3 -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/third_party/simpleini -I/usr/include/SDL2 -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/src/. -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/src/.. -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/src/../third_party -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/src/observable -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/build/src/base -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/third_party/duktape -fomit-frame-pointer -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -flto=auto -DNDEBUG -O2 -g -DNDEBUG -MD -MT src/script/CMakeFiles/duktape.dir/__/__/third_party/duktape/duktape.c.o -MF CMakeFiles/duktape.dir/__/__/third_party/duktape/duktape.c.o.d -o CMakeFiles/duktape.dir/__/__/third_party/duktape/duktape.c.o -c /home/abuild/rpmbuild/BUILD/LibreSprite-1.0/third_party/duktape/duktape.c
[ 21%] Building CXX object src/css/CMakeFiles/css-lib.dir/sheet.cpp.o
cd /home/abuild/rpmbuild/BUILD/LibreSprite-1.0/build/src/css && /usr/bin/g++-10 -DHAVE_CONFIG_H -DNDEBUG -DSCRIPT_ENGINE_LUA=1 -DUSE_SDL2_BACKEND -I/usr/include/libpng16 -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/lua5.3 -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/third_party/simpleini -I/usr/include/SDL2 -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/src/. -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/src/.. -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/src/../third_party -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/src/observable -I/home/abuild/rpmbuild/BUILD/LibreSprite-1.0/build/src/base -fomit-frame-pointer -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -flto=auto -DNDEBUG -std=c++14 -Wall -Wno-switch -std=gnu++11 -O2 -g -DNDEBUG -MD -MT src/css/CMakeFiles/css-lib.dir/sheet.cpp.o -MF CMakeFiles/css-lib.dir/sheet.cpp.o.d -o CMakeFiles/css-lib.dir/sheet.cpp.o -c /home/abuild/rpmbuild/BUILD

First uses /usr/bin/cc (gcc11), second one as specified gcc10

Results in:

lto1: fatal error: bytecode stream in file '../lib/libduktape.a' generated with LTO version 11.2 instead of the expected 9.4

To Reproduce

Compile with recent gcc10-10.3.1 use option -DCMAKE_CXX_COMPILER=g++-10

OS/Hardware

Linux openSUSE Tumbleweed i586 or x86_64

Additional context

Complete build log (will change when package is updated!):
https://build.opensuse.org/package/live_build_log/games:tools/libresprite/openSUSE_Tumbleweed/i586

P.S.

For packaging it's recommended NOT to use embedded version, but rather the packaged ones of the OS.

[stoecker]

Note - the live build log soon no longer shows the resulting build failure, as the option is now only used for openSUSE <= 15.4 where gcc7 and gcc10 are used which luckily have the same LTO bytecode stream.