Build Qt5 cross-builder with raspbian sysroot: compiling with the sysroot

Whack-A-Mole machines from <https://commons.wikimedia.org/wiki/File:Whac-A-Mole_Cedar_Point.jpg>
Whack-A-Mole machines from <https://commons.wikimedia.org/wiki/File:Whac-A-Mole_Cedar_Point.jpg>

This is part of a series of posts on compiling a custom version of Qt5 in order to develop for both amd64 and a Raspberry Pi.

Now that I have a sysroot, I try to use it to build Qt5 with QtWebEngine.

Nothing seems to work straightforwardly with Qt5's build system, and hit an endless series of significant blockers to try and work around.


Problem in wayland code

QtWayland's source currently does not compile:

../../../hardwareintegration/client/brcm-egl/qwaylandbrcmeglwindow.cpp: In constructor ‘QtWaylandClient::QWaylandBrcmEglWindow::QWaylandBrcmEglWindow(QWindow*)’:
../../../hardwareintegration/client/brcm-egl/qwaylandbrcmeglwindow.cpp:131:67: error: no matching function for call to ‘QtWaylandClient::QWaylandWindow::QWaylandWindow(QWindow*&)’
     , m_eventQueue(wl_display_create_queue(mDisplay->wl_display()))
                                                                   ^
In file included from ../../../../include/QtWaylandClient/5.15.0/QtWaylandClient/private/qwaylandwindow_p.h:1,
                 from ../../../hardwareintegration/client/brcm-egl/qwaylandbrcmeglwindow.h:43,
                 from ../../../hardwareintegration/client/brcm-egl/qwaylandbrcmeglwindow.cpp:40:
../../../../include/QtWaylandClient/5.15.0/QtWaylandClient/private/../../../../../src/client/qwaylandwindow_p.h:97:5: note: candidate: ‘QtWaylandClient::QWaylandWindow::QWaylandWindow(QWindow*, QtWayland
Client::QWaylandDisplay*)’
     QWaylandWindow(QWindow *window, QWaylandDisplay *display);
     ^~~~~~~~~~~~~~
../../../../include/QtWaylandClient/5.15.0/QtWaylandClient/private/../../../../../src/client/qwaylandwindow_p.h:97:5: note:   candidate expects 2 arguments, 1 provided
make[5]: Leaving directory '/home/build/armhf/qt-everywhere-src-5.15.0/qttools/src/qdoc'

I am not trying to debug here. I understand that Wayland support is not a requirement, and I'm adding -skip wayland to Qt5's configure options.

Next round.

nss not found

Qt5 embeds Chrome's sources. Chrome's sources require libnss3-dev to be available for both host and target architectures. Although I now have it installed both on the build system and in the sysroot, the pkg-config wrapper that Qt5 hooks into its Chrome's sources, failes to find it:

Command: /usr/bin/python2 /home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/3rdparty/chromium/build/config/linux/pkg-config.py -s /home/build/sysroot/ -a arm -p /usr/bin/arm-linux-gnueabihf-pkg-config --system_libdir lib nss -v -lssl3
Returned 1.
stderr:

Package nss was not found in the pkg-config search path.
Perhaps you should add the directory containing `nss.pc'
to the PKG_CONFIG_PATH environment variable
No package 'nss' found
Traceback (most recent call last):
  File "/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/3rdparty/chromium/build/config/linux/pkg-config.py", line 248, in <module>
    sys.exit(main())
  File "/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/3rdparty/chromium/build/config/linux/pkg-config.py", line 143, in main
    prefix = GetPkgConfigPrefixToStrip(options, args)
  File "/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/3rdparty/chromium/build/config/linux/pkg-config.py", line 82, in GetPkgConfigPrefixToStrip
    "--variable=prefix"] + args, env=os.environ).decode('utf-8')
  File "/usr/lib/python2.7/subprocess.py", line 223, in check_output
    raise CalledProcessError(retcode, cmd, output=output)
subprocess.CalledProcessError: Command '['/usr/bin/arm-linux-gnueabihf-pkg-config', '--variable=prefix', 'nss']' returned non-zero exit status 1

See //build/config/linux/nss/BUILD.gn:15:3: whence it was called.
  pkg_config("system_nss_no_ssl_config") {
  ^---------------------------------------
See //crypto/BUILD.gn:218:25: which caused the file to be included.
    public_configs += [ "//build/config/linux/nss:system_nss_no_ssl_config" ]
                        ^--------------------------------------------------
Project ERROR: GN run error!

It's trying to look into $SYSROOT/usr/lib/pkgconfig, while it should be $SYSROOT//usr/lib/arm-linux-gnueabihf/pkgconfig.

I worked around this this patch to qtwebengine/src/3rdparty/chromium/build/config/linux/pkg-config.py:

--- pkg-config.py.orig  2020-07-16 11:46:21.005373002 +0200
+++ pkg-config.py   2020-07-16 11:46:02.605296967 +0200
@@ -61,6 +61,7 @@

   libdir = sysroot + '/usr/' + options.system_libdir + '/pkgconfig'
   libdir += ':' + sysroot + '/usr/share/pkgconfig'
+  libdir += ':' + sysroot + '/usr/lib/arm-linux-gnueabihf/pkgconfig'
   os.environ['PKG_CONFIG_LIBDIR'] = libdir
   return libdir

Next round.

g++ 8.3.0 Internal Compiler Error

Qt5's sources embed Chrome's sources that embed the skia library sources.

One of the skia library sources, when cross-compiled to ARM with -O1 or -O2 with g++ 8.3.0, produces an Internal Compiler Error:

/usr/bin/arm-linux-gnueabihf-g++ -MMD -MF obj/skia/skcms/skcms.o.d -DUSE_UDEV -DUSE_AURA=1 -DUSE_NSS_CERTS=1 -DUSE_OZONE=1 -DOFFICIAL_BUILD -DTOOLKIT_QT -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -DNO_UNWIND_TABLES -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DCR_SYSROOT_HASH=76e6068f9f6954e2ab1ff98ce5fa236d3d85bcbd -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -I../../3rdparty/chromium/third_party/skia/include/third_party/skcms -Igen -I../../3rdparty/chromium -w -std=c11 -mfp16-format=ieee -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -fno-unwind-tables -fno-asynchronous-unwind-tables -fPIC -pipe -pthread -march=armv7-a -mfloat-abi=hard -mtune=generic-armv7-a -mfpu=vfpv3-d16 -mthumb -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wno-psabi -Wno-unused-local-typedefs -Wno-maybe-uninitialized -Wno-deprecated-declarations -fno-delete-null-pointer-checks -Wno-comments -Wno-packed-not-aligned -Wno-dangling-else -Wno-missing-field-initializers -Wno-unused-parameter -O2 -fno-ident -fdata-sections -ffunction-sections -fno-omit-frame-pointer -g0 -fvisibility=hidden -std=gnu++14 -Wno-narrowing -Wno-class-memaccess -Wno-attributes -Wno-class-memaccess -Wno-subobject-linkage -Wno-invalid-offsetof -Wno-return-type -Wno-deprecated-copy -fno-exceptions -fno-rtti --sysroot=../../../../../../sysroot/ -fvisibility-inlines-hidden -c ../../3rdparty/chromium/third_party/skia/third_party/skcms/skcms.cc -o obj/skia/skcms/skcms.o
during RTL pass: expand
In file included from ../../3rdparty/chromium/third_party/skia/third_party/skcms/skcms.cc:2053:
../../3rdparty/chromium/third_party/skia/third_party/skcms/src/Transform_inl.h: In function ‘void baseline::exec_ops(const Op*, const void**, const char*, char*, int)’:
../../3rdparty/chromium/third_party/skia/third_party/skcms/src/Transform_inl.h:766:13: internal compiler error: in convert_move, at expr.c:218
 static void exec_ops(const Op* ops, const void** args,
             ^~~~~~~~
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-8/README.Bugs> for instructions.

I reported the bug at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96206

Since this source compiles with -O0, I attempted to fix this by editing qtwebkit/src/3rdparty/chromium/build/config/compiler/BUILD.gn and replacing instances of -O1 and -O2 with -O0.

Spoiler: wrong attempt. We'll see it in the next round.

Impossible constraint in asm

Qt5's sources embed Chrome's sources that embed the ffmpeg library sources. Even if ffmpeg's development libraries are present both in the host and in the target system, the build system insists in compiling and using the bundled version.

Unfortunately, using -O0 breaks the build of ffmpeg:

/usr/bin/arm-linux-gnueabihf-gcc -MMD -MF obj/third_party/ffmpeg/ffmpeg_internal/opus.o.d -DHAVE_AV_CONFIG_H -D_POSIX_C_SOURCE=200112 -D_XOPEN_SOURCE=600 -DPIC -DFFMPEG_CONFIGURATION=NULL -DCHROMIUM_NO_LOGGING -D_ISOC99_SOURCE -D_LARGEFILE_SOURCE -DUSE_UDEV -DUSE_AURA=1 -DUSE_NSS_CERTS=1 -DUSE_OZONE=1 -DOFFICIAL_BUILD -DTOOLKIT_QT -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -DNO_UNWIND_TABLES -DCR_SYSROOT_HASH=76e6068f9f6954e2ab1ff98ce5fa236d3d85bcbd -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DOPUS_FIXED_POINT -I../../3rdparty/chromium/third_party/ffmpeg/chromium/config/Chromium/linux/arm -I../../3rdparty/chromium/third_party/ffmpeg -I../../3rdparty/chromium/third_party/ffmpeg/compat/atomics/gcc -Igen -I../../3rdparty/chromium -I../../3rdparty/chromium/third_party/opus/src/include -fPIC -Wno-deprecated-declarations -fomit-frame-pointer -w -std=c99 -pthread -fno-math-errno -fno-signed-zeros -fno-tree-vectorize -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -fno-unwind-tables -fno-asynchronous-unwind-tables -fPIC -pipe -pthread -march=armv7-a -mfloat-abi=hard -mtune=generic-armv7-a -mfpu=vfpv3-d16 -mthumb -g0 -fvisibility=hidden -Wno-psabi -Wno-unused-local-typedefs -Wno-maybe-uninitialized -Wno-deprecated-declarations -fno-delete-null-pointer-checks -Wno-comments -Wno-packed-not-aligned -Wno-dangling-else -Wno-missing-field-initializers -Wno-unused-parameter -O0 -fno-ident -fdata-sections -ffunction-sections -std=gnu11 --sysroot=../../../../../../sysroot/ -c ../../3rdparty/chromium/third_party/ffmpeg/libavcodec/opus.c -o obj/third_party/ffmpeg/ffmpeg_internal/opus.o
In file included from ../../3rdparty/chromium/third_party/ffmpeg/libavutil/intmath.h:30,
                 from ../../3rdparty/chromium/third_party/ffmpeg/libavutil/common.h:106,
                 from ../../3rdparty/chromium/third_party/ffmpeg/libavutil/avutil.h:296,
                 from ../../3rdparty/chromium/third_party/ffmpeg/libavutil/audio_fifo.h:30,
                 from ../../3rdparty/chromium/third_party/ffmpeg/libavcodec/opus.h:28,
                 from ../../3rdparty/chromium/third_party/ffmpeg/libavcodec/opus_celt.h:29,
                 from ../../3rdparty/chromium/third_party/ffmpeg/libavcodec/opus.c:32:
../../3rdparty/chromium/third_party/ffmpeg/libavcodec/opus.c: In function ‘ff_celt_quant_bands’:
../../3rdparty/chromium/third_party/ffmpeg/libavutil/arm/intmath.h:77:5: error: impossible constraint in ‘asm’
     __asm__ ("usat %0, %2, %1" : "=r"(x) : "r"(a), "i"(p));
     ^~~~~~~

The same source compiles with using -O2 instead of -O0.

I worked around this by undoing the previous change, and limiting -O0 to just the source that causes the Internal Compiler Error.

I edited qtwebengine/src/3rdparty/chromium/third_party/skia/third_party/skcms/skcms.cc to prepend:

#pragma GCC push_options
#pragma GCC optimize ("O0")

and append:

#pragma GCC pop_options

Next round.

Missing build-deps for i386 code

Qt5's sources embed Chrome's sources that embed the V8 library sources.

For some reason, torque, that is part of V8, wants to build some of its sources into 32 bit code with -m32, and I did not have i386 cross-compilation libraries installed:

/usr/bin/g++ -MMD -MF v8_snapshot/obj/v8/torque_base/csa-generator.o.d -DUSE_UDEV -DUSE_AURA=1 -DUSE_NSS_CERTS=1 -DUSE_OZONE=1 -DOFFICIAL_BUILD -DTOOLKIT_QT -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -DNO_UNWIND_TABLES -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DV8_TYPED_ARRAY_MAX_SIZE_IN_HEAP=64 -DENABLE_MINOR_MC -DV8_INTL_SUPPORT -DV8_CONCURRENT_MARKING -DV8_ENABLE_LAZY_SOURCE_POSITIONS -DV8_EMBEDDED_BUILTINS -DV8_SHARED_RO_HEAP -DV8_WIN64_UNWINDING_INFO -DV8_ENABLE_REGEXP_INTERPRETER_THREADED_DISPATCH -DV8_31BIT_SMIS_ON_64BIT_ARCH -DV8_DEPRECATION_WARNINGS -DV8_TARGET_ARCH_ARM -DCAN_USE_ARMV7_INSTRUCTIONS -DCAN_USE_VFP3_INSTRUCTIONS -DUSE_EABI_HARDFLOAT=1 -DV8_HAVE_TARGET_OS -DV8_TARGET_OS_LINUX -DDISABLE_UNTRUSTED_CODE_MITIGATIONS -DV8_31BIT_SMIS_ON_64BIT_ARCH -DV8_DEPRECATION_WARNINGS -Iv8_snapshot/gen -I../../3rdparty/chromium -I../../3rdparty/chromium/v8 -Iv8_snapshot/gen/v8 -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -fno-unwind-tables -fno-asynchronous-unwind-tables -fPIC -pipe -pthread -m32 -msse2 -mfpmath=sse -mmmx -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wno-unused-local-typedefs -Wno-maybe-uninitialized -Wno-deprecated-declarations -fno-delete-null-pointer-checks -Wno-comments -Wno-packed-not-aligned -Wno-dangling-else -Wno-missing-field-initializers -Wno-unused-parameter -fno-omit-frame-pointer -g0 -fvisibility=hidden -Wno-strict-overflow -Wno-return-type -O3 -fno-ident -fdata-sections -ffunction-sections -std=gnu++14 -Wno-narrowing -Wno-class-memaccess -Wno-attributes -Wno-class-memaccess -Wno-subobject-linkage -Wno-invalid-offsetof -Wno-return-type -Wno-deprecated-copy -fvisibility-inlines-hidden -fexceptions -frtti -c ../../3rdparty/chromium/v8/src/torque/csa-generator.cc -o v8_snapshot/obj/v8/torque_base/csa-generator.o
In file included from ../../3rdparty/chromium/v8/src/torque/csa-generator.h:8,
                 from ../../3rdparty/chromium/v8/src/torque/csa-generator.cc:5:
/usr/include/c++/8/iostream:38:10: fatal error: bits/c++config.h: No such file or directory
 #include <bits/c++config.h>
          ^~~~~~~~~~~~~~~~~~
compilation terminated.

New build dependencies needed:

apt install lib32stdc++-8-dev
apt install libc6-dev-i386
dpkg --add-architecture i386
apt install linux-libc-dev:i386

Next round.

OpenGL build issues

Next bump are OpenGL related compiler issues:

/usr/bin/arm-linux-gnueabihf-g++ -MMD -MF obj/QtWebEngineCore/gl_ozone_glx_qt.o.d -DCHROMIUM_VERSION=\"80.0.3987.163\" -DUSE_UDEV -DUSE_AURA=1 -DUSE_NSS_CERTS=1 -DUSE_OZONE=1 -DOFFICIAL_BUILD -DTOOLKIT_QT -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -DNO_UNWIND_TABLES -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DCR_SYSROOT_HASH=76e6068f9f6954e2ab1ff98ce5fa236d3d85bcbd -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DQT_NO_LINKED_LIST -DQT_NO_KEYWORDS -DQT_USE_QSTRINGBUILDER -DQ_FORWARD_DECLARE_OBJC_CLASS=QT_FORWARD_DECLARE_CLASS -DQTWEBENGINECORE_VERSION_STR=\"5.15.0\" -DQTWEBENGINEPROCESS_NAME=\"QtWebEngineProcess\" -DBUILDING_CHROMIUM -DQTWEBENGINE_EMBEDDED_SWITCHES -DQT_NO_EXCEPTIONS -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -DQT_NO_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QMLMODELS_LIB -DQT_WEBCHANNEL_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_POSITIONING_LIB -DQT_CORE_LIB -DQT_WEBENGINECOREHEADERS_LIB -DVK_NO_PROTOTYPES -DGL_GLEXT_PROTOTYPES -DUSE_GLX -DUSE_EGL -DGOOGLE_PROTOBUF_NO_RTTI -DGOOGLE_PROTOBUF_NO_STATIC_INITIALIZER -DHAVE_PTHREAD -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0 -DUSE_CHROMIUM_ICU=1 -DU_STATIC_IMPLEMENTATION -DICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_FILE -DUCHAR_TYPE=uint16_t -DWEBRTC_NON_STATIC_TRACE_EVENT_HANDLERS=0 -DWEBRTC_CHROMIUM_BUILD -DWEBRTC_POSIX -DWEBRTC_LINUX -DABSL_ALLOCATOR_NOTHROW=1 -DWEBRTC_USE_BUILTIN_ISAC_FIX=1 -DWEBRTC_USE_BUILTIN_ISAC_FLOAT=0 -DHAVE_SCTP -DNO_MAIN_THREAD_WRAPPING -DSK_HAS_PNG_LIBRARY -DSK_HAS_WEBP_LIBRARY -DSK_USER_CONFIG_HEADER=\"../../skia/config/SkUserConfig.h\" -DSK_GL -DSK_HAS_JPEG_LIBRARY -DSK_USE_LIBGIFCODEC -DSK_VULKAN_HEADER=\"../../skia/config/SkVulkanConfig.h\" -DSK_VULKAN=1 -DSK_SUPPORT_GPU=1 -DSK_GPU_WORKAROUNDS_HEADER=\"gpu/config/gpu_driver_bug_workaround_autogen.h\" -DVK_NO_PROTOTYPES -DLEVELDB_PLATFORM_CHROMIUM=1 -DLEVELDB_PLATFORM_CHROMIUM=1 -DV8_31BIT_SMIS_ON_64BIT_ARCH -DV8_DEPRECATION_WARNINGS -I../../3rdparty/chromium/skia/config -I../../3rdparty/chromium/third_party -I../../3rdparty/chromium/third_party/boringssl/src/include -I../../3rdparty/chromium/third_party/skia/include/core -Igen -I../../3rdparty/chromium -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core/api -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQuick/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQuick/5.15.0/QtQuick -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtGui/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtGui/5.15.0/QtGui -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQuick -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtGui -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQmlModels/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQmlModels/5.15.0/QtQmlModels -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQml/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQml/5.15.0/QtQml -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtCore/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtCore/5.15.0/QtCore -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQmlModels -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebchannel/include -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebchannel/include/QtWebChannel -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQml -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtNetwork -I/home/build/armhf/qt-everywhere-src-5.15.0/qtlocation/include -I/home/build/armhf/qt-everywhere-src-5.15.0/qtlocation/include/QtPositioning -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtCore -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/include -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/include/QtWebEngineCore -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/include/QtWebEngineCore/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/include/QtWebEngineCore/5.15.0/QtWebEngineCore -I.moc -I/home/build/sysroot/opt/vc/include -I/home/build/sysroot/opt/vc/include/interface/vcos/pthreads -I/home/build/sysroot/opt/vc/include/interface/vmcs_host/linux -Igen/.moc -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/mkspecs/devices/linux-rasp-pi2-g++ -Igen -Igen -I../../3rdparty/chromium/third_party/libyuv/include -Igen -I../../3rdparty/chromium/third_party/jsoncpp/source/include -I../../3rdparty/chromium/third_party/jsoncpp/generated -Igen -Igen -I../../3rdparty/chromium/third_party/khronos -I../../3rdparty/chromium/gpu -I../../3rdparty/chromium/third_party/vulkan/include -I../../3rdparty/chromium/third_party/perfetto/include -Igen/third_party/perfetto/build_config -Igen -Igen -Igen/third_party/dawn/src/include -I../../3rdparty/chromium/third_party/dawn/src/include -Igen -I../../3rdparty/chromium/third_party/boringssl/src/include -I../../3rdparty/chromium/third_party/protobuf/src -Igen/protoc_out -I../../3rdparty/chromium/third_party/protobuf/src -I../../3rdparty/chromium/third_party/ced/src -I../../3rdparty/chromium/third_party/icu/source/common -I../../3rdparty/chromium/third_party/icu/source/i18n -I../../3rdparty/chromium/third_party/webrtc_overrides -I../../3rdparty/chromium/third_party/webrtc -Igen/third_party/webrtc -I../../3rdparty/chromium/third_party/abseil-cpp -I../../3rdparty/chromium/third_party/skia -I../../3rdparty/chromium/third_party/libgifcodec -I../../3rdparty/chromium/third_party/vulkan/include -I../../3rdparty/chromium/third_party/skia/third_party/vulkanmemoryallocator -I../../3rdparty/chromium/third_party/vulkan/include -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -I../../3rdparty/chromium/third_party/crashpad/crashpad -I../../3rdparty/chromium/third_party/crashpad/crashpad/compat/non_mac -I../../3rdparty/chromium/third_party/crashpad/crashpad/compat/linux -I../../3rdparty/chromium/third_party/crashpad/crashpad/compat/non_win -I../../3rdparty/chromium/third_party/libwebm/source -I../../3rdparty/chromium/third_party/leveldatabase -I../../3rdparty/chromium/third_party/leveldatabase/src -I../../3rdparty/chromium/third_party/leveldatabase/src/include -I../../3rdparty/chromium/v8/include -Igen/v8/include -I../../3rdparty/chromium/third_party/mesa_headers -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -fno-unwind-tables -fno-asynchronous-unwind-tables -fPIC -pipe -pthread -march=armv7-a -mfloat-abi=hard -mtune=generic-armv7-a -mfpu=vfpv3-d16 -mthumb -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wno-psabi -Wno-unused-local-typedefs -Wno-maybe-uninitialized -Wno-deprecated-declarations -fno-delete-null-pointer-checks -Wno-comments -Wno-packed-not-aligned -Wno-dangling-else -Wno-missing-field-initializers -Wno-unused-parameter -O2 -fno-ident -fdata-sections -ffunction-sections -fno-omit-frame-pointer -g0 -fvisibility=hidden -g -O2 -fdebug-prefix-map=/home/build/armhf/qt-everywhere-src-5.15.0=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -O2 -fno-exceptions -Wall -Wextra -D_REENTRANT -I/home/build/sysroot/usr/include/nss -I/home/build/sysroot/usr/include/nspr -std=gnu++14 -Wno-narrowing -Wno-class-memaccess -Wno-attributes -Wno-class-memaccess -Wno-subobject-linkage -Wno-invalid-offsetof -Wno-return-type -Wno-deprecated-copy -fno-exceptions -fno-rtti --sysroot=../../../../../../sysroot/ -fvisibility-inlines-hidden -g -O2 -fdebug-prefix-map=/home/build/armhf/qt-everywhere-src-5.15.0=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -O2 -std=gnu++1y -fno-exceptions -Wall -Wextra -D_REENTRANT -Wno-unused-parameter -Wno-unused-variable -Wno-deprecated-declarations -c /home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core/ozone/gl_ozone_glx_qt.cpp -o obj/QtWebEngineCore/gl_ozone_glx_qt.o
In file included from ../../3rdparty/chromium/ui/gl/gl_bindings.h:497,
                 from ../../3rdparty/chromium/ui/gl/gl_gl_api_implementation.h:12,
                 from /home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core/ozone/gl_ozone_glx_qt.cpp:49:
../../3rdparty/chromium/ui/gl/gl_bindings_autogen_egl.h:227:5: error: ‘EGLSetBlobFuncANDROID’ has not been declared
     EGLSetBlobFuncANDROID set,
     ^~~~~~~~~~~~~~~~~~~~~
../../3rdparty/chromium/ui/gl/gl_bindings_autogen_egl.h:228:5: error: ‘EGLGetBlobFuncANDROID’ has not been declared
     EGLGetBlobFuncANDROID get);
     ^~~~~~~~~~~~~~~~~~~~~
../../3rdparty/chromium/ui/gl/gl_bindings_autogen_egl.h:571:46: error: ‘EGLSetBlobFuncANDROID’ has not been declared
                                              EGLSetBlobFuncANDROID set,
                                              ^~~~~~~~~~~~~~~~~~~~~
../../3rdparty/chromium/ui/gl/gl_bindings_autogen_egl.h:572:46: error: ‘EGLGetBlobFuncANDROID’ has not been declared
                                              EGLGetBlobFuncANDROID get) = 0;
                                              ^~~~~~~~~~~~~~~~~~~~~
cc1plus: warning: unrecognized command line option ‘-Wno-deprecated-copy’
/usr/bin/arm-linux-gnueabihf-g++ -MMD -MF obj/QtWebEngineCore/display_gl_output_surface.o.d -DCHROMIUM_VERSION=\"80.0.3987.163\" -DUSE_UDEV -DUSE_AURA=1 -DUSE_NSS_CERTS=1 -DUSE_OZONE=1 -DOFFICIAL_BUILD -DTOOLKIT_QT -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -DNO_UNWIND_TABLES -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DCR_SYSROOT_HASH=76e6068f9f6954e2ab1ff98ce5fa236d3d85bcbd -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DQT_NO_LINKED_LIST -DQT_NO_KEYWORDS -DQT_USE_QSTRINGBUILDER -DQ_FORWARD_DECLARE_OBJC_CLASS=QT_FORWARD_DECLARE_CLASS -DQTWEBENGINECORE_VERSION_STR=\"5.15.0\" -DQTWEBENGINEPROCESS_NAME=\"QtWebEngineProcess\" -DBUILDING_CHROMIUM -DQTWEBENGINE_EMBEDDED_SWITCHES -DQT_NO_EXCEPTIONS -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -DQT_NO_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QMLMODELS_LIB -DQT_WEBCHANNEL_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_POSITIONING_LIB -DQT_CORE_LIB -DQT_WEBENGINECOREHEADERS_LIB -DVK_NO_PROTOTYPES -DGL_GLEXT_PROTOTYPES -DUSE_GLX -DUSE_EGL -DGOOGLE_PROTOBUF_NO_RTTI -DGOOGLE_PROTOBUF_NO_STATIC_INITIALIZER -DHAVE_PTHREAD -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0 -DUSE_CHROMIUM_ICU=1 -DU_STATIC_IMPLEMENTATION -DICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_FILE -DUCHAR_TYPE=uint16_t -DWEBRTC_NON_STATIC_TRACE_EVENT_HANDLERS=0 -DWEBRTC_CHROMIUM_BUILD -DWEBRTC_POSIX -DWEBRTC_LINUX -DABSL_ALLOCATOR_NOTHROW=1 -DWEBRTC_USE_BUILTIN_ISAC_FIX=1 -DWEBRTC_USE_BUILTIN_ISAC_FLOAT=0 -DHAVE_SCTP -DNO_MAIN_THREAD_WRAPPING -DSK_HAS_PNG_LIBRARY -DSK_HAS_WEBP_LIBRARY -DSK_USER_CONFIG_HEADER=\"../../skia/config/SkUserConfig.h\" -DSK_GL -DSK_HAS_JPEG_LIBRARY -DSK_USE_LIBGIFCODEC -DSK_VULKAN_HEADER=\"../../skia/config/SkVulkanConfig.h\" -DSK_VULKAN=1 -DSK_SUPPORT_GPU=1 -DSK_GPU_WORKAROUNDS_HEADER=\"gpu/config/gpu_driver_bug_workaround_autogen.h\" -DVK_NO_PROTOTYPES -DLEVELDB_PLATFORM_CHROMIUM=1 -DLEVELDB_PLATFORM_CHROMIUM=1 -DV8_31BIT_SMIS_ON_64BIT_ARCH -DV8_DEPRECATION_WARNINGS -I../../3rdparty/chromium/skia/config -I../../3rdparty/chromium/third_party -I../../3rdparty/chromium/third_party/boringssl/src/include -I../../3rdparty/chromium/third_party/skia/include/core -Igen -I../../3rdparty/chromium -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core/api -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQuick/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQuick/5.15.0/QtQuick -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtGui/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtGui/5.15.0/QtGui -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQuick -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtGui -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQmlModels/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQmlModels/5.15.0/QtQmlModels -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQml/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQml/5.15.0/QtQml -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtCore/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtCore/5.15.0/QtCore -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQmlModels -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebchannel/include -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebchannel/include/QtWebChannel -I/home/build/armhf/qt-everywhere-src-5.15.0/qtdeclarative/include/QtQml -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtNetwork -I/home/build/armhf/qt-everywhere-src-5.15.0/qtlocation/include -I/home/build/armhf/qt-everywhere-src-5.15.0/qtlocation/include/QtPositioning -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/include/QtCore -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/include -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/include/QtWebEngineCore -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/include/QtWebEngineCore/5.15.0 -I/home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/include/QtWebEngineCore/5.15.0/QtWebEngineCore -I.moc -I/home/build/sysroot/opt/vc/include -I/home/build/sysroot/opt/vc/include/interface/vcos/pthreads -I/home/build/sysroot/opt/vc/include/interface/vmcs_host/linux -Igen/.moc -I/home/build/armhf/qt-everywhere-src-5.15.0/qtbase/mkspecs/devices/linux-rasp-pi2-g++ -Igen -Igen -I../../3rdparty/chromium/third_party/libyuv/include -Igen -I../../3rdparty/chromium/third_party/jsoncpp/source/include -I../../3rdparty/chromium/third_party/jsoncpp/generated -Igen -Igen -I../../3rdparty/chromium/third_party/khronos -I../../3rdparty/chromium/gpu -I../../3rdparty/chromium/third_party/vulkan/include -I../../3rdparty/chromium/third_party/perfetto/include -Igen/third_party/perfetto/build_config -Igen -Igen -Igen/third_party/dawn/src/include -I../../3rdparty/chromium/third_party/dawn/src/include -Igen -I../../3rdparty/chromium/third_party/boringssl/src/include -I../../3rdparty/chromium/third_party/protobuf/src -Igen/protoc_out -I../../3rdparty/chromium/third_party/protobuf/src -I../../3rdparty/chromium/third_party/ced/src -I../../3rdparty/chromium/third_party/icu/source/common -I../../3rdparty/chromium/third_party/icu/source/i18n -I../../3rdparty/chromium/third_party/webrtc_overrides -I../../3rdparty/chromium/third_party/webrtc -Igen/third_party/webrtc -I../../3rdparty/chromium/third_party/abseil-cpp -I../../3rdparty/chromium/third_party/skia -I../../3rdparty/chromium/third_party/libgifcodec -I../../3rdparty/chromium/third_party/vulkan/include -I../../3rdparty/chromium/third_party/skia/third_party/vulkanmemoryallocator -I../../3rdparty/chromium/third_party/vulkan/include -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -Igen/third_party/perfetto -I../../3rdparty/chromium/third_party/crashpad/crashpad -I../../3rdparty/chromium/third_party/crashpad/crashpad/compat/non_mac -I../../3rdparty/chromium/third_party/crashpad/crashpad/compat/linux -I../../3rdparty/chromium/third_party/crashpad/crashpad/compat/non_win -I../../3rdparty/chromium/third_party/libwebm/source -I../../3rdparty/chromium/third_party/leveldatabase -I../../3rdparty/chromium/third_party/leveldatabase/src -I../../3rdparty/chromium/third_party/leveldatabase/src/include -I../../3rdparty/chromium/v8/include -Igen/v8/include -I../../3rdparty/chromium/third_party/mesa_headers -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -fno-unwind-tables -fno-asynchronous-unwind-tables -fPIC -pipe -pthread -march=armv7-a -mfloat-abi=hard -mtune=generic-armv7-a -mfpu=vfpv3-d16 -mthumb -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wno-psabi -Wno-unused-local-typedefs -Wno-maybe-uninitialized -Wno-deprecated-declarations -fno-delete-null-pointer-checks -Wno-comments -Wno-packed-not-aligned -Wno-dangling-else -Wno-missing-field-initializers -Wno-unused-parameter -O2 -fno-ident -fdata-sections -ffunction-sections -fno-omit-frame-pointer -g0 -fvisibility=hidden -g -O2 -fdebug-prefix-map=/home/build/armhf/qt-everywhere-src-5.15.0=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -O2 -fno-exceptions -Wall -Wextra -D_REENTRANT -I/home/build/sysroot/usr/include/nss -I/home/build/sysroot/usr/include/nspr -std=gnu++14 -Wno-narrowing -Wno-class-memaccess -Wno-attributes -Wno-class-memaccess -Wno-subobject-linkage -Wno-invalid-offsetof -Wno-return-type -Wno-deprecated-copy -fno-exceptions -fno-rtti --sysroot=../../../../../../sysroot/ -fvisibility-inlines-hidden -g -O2 -fdebug-prefix-map=/home/build/armhf/qt-everywhere-src-5.15.0=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -O2 -std=gnu++1y -fno-exceptions -Wall -Wextra -D_REENTRANT -Wno-unused-parameter -Wno-unused-variable -Wno-deprecated-declarations -c /home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core/compositor/display_gl_output_surface.cpp -o obj/QtWebEngineCore/display_gl_output_surface.o
In file included from ../../3rdparty/chromium/gpu/command_buffer/client/gles2_interface.h:8,
                 from ../../3rdparty/chromium/gpu/command_buffer/client/client_transfer_cache.h:15,
                 from ../../3rdparty/chromium/gpu/command_buffer/client/gles2_implementation.h:28,
                 from /home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core/compositor/display_gl_output_surface.cpp:47:
/home/build/sysroot/opt/vc/include/GLES2/gl2.h:78: warning: "GL_FALSE" redefined
 #define GL_FALSE                          (GLboolean)0

In file included from ../../3rdparty/chromium/gpu/command_buffer/client/client_context_state.h:10,
                 from ../../3rdparty/chromium/gpu/command_buffer/client/gles2_implementation.h:27,
                 from /home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core/compositor/display_gl_output_surface.cpp:47:
../../3rdparty/chromium/third_party/khronos/GLES3/gl3.h:85: note: this is the location of the previous definition
 #define GL_FALSE                          0

In file included from ../../3rdparty/chromium/gpu/command_buffer/client/gles2_interface.h:8,
                 from ../../3rdparty/chromium/gpu/command_buffer/client/client_transfer_cache.h:15,
                 from ../../3rdparty/chromium/gpu/command_buffer/client/gles2_implementation.h:28,
                 from /home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core/compositor/display_gl_output_surface.cpp:47:
/home/build/sysroot/opt/vc/include/GLES2/gl2.h:79: warning: "GL_TRUE" redefined
 #define GL_TRUE                           (GLboolean)1

In file included from ../../3rdparty/chromium/gpu/command_buffer/client/client_context_state.h:10,
                 from ../../3rdparty/chromium/gpu/command_buffer/client/gles2_implementation.h:27,
                 from /home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core/compositor/display_gl_output_surface.cpp:47:
../../3rdparty/chromium/third_party/khronos/GLES3/gl3.h:86: note: this is the location of the previous definition
 #define GL_TRUE                           1

In file included from ../../3rdparty/chromium/gpu/command_buffer/client/gles2_interface.h:8,
                 from ../../3rdparty/chromium/gpu/command_buffer/client/client_transfer_cache.h:15,
                 from ../../3rdparty/chromium/gpu/command_buffer/client/gles2_implementation.h:28,
                 from /home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core/compositor/display_gl_output_surface.cpp:47:
/home/build/sysroot/opt/vc/include/GLES2/gl2.h:600:37: error: conflicting declaration of C function ‘void glShaderSource(GLuint, GLsizei, const GLchar**, const GLint*)’
 GL_APICALL void         GL_APIENTRY glShaderSource (GLuint shader, GLsizei count, const GLchar** string, const GLint* length);
                                     ^~~~~~~~~~~~~~
In file included from ../../3rdparty/chromium/gpu/command_buffer/client/client_context_state.h:10,
                 from ../../3rdparty/chromium/gpu/command_buffer/client/gles2_implementation.h:27,
                 from /home/build/armhf/qt-everywhere-src-5.15.0/qtwebengine/src/core/compositor/display_gl_output_surface.cpp:47:
../../3rdparty/chromium/third_party/khronos/GLES3/gl3.h:624:29: note: previous declaration ‘void glShaderSource(GLuint, GLsizei, const GLchar* const*, const GLint*)’
 GL_APICALL void GL_APIENTRY glShaderSource (GLuint shader, GLsizei count, const GLchar *const*string, const GLint *length);
                             ^~~~~~~~~~~~~~
cc1plus: warning: unrecognized command line option ‘-Wno-deprecated-copy’

I'm out of the allocated hour budget, and I'll stop here for now.

Building Qt5 has been providing some of the most nightmarish work time in my entire professional life. If my daily job became being required to deal with this kind of insanity, I would strongly invest in a change of career.

Update

Andreas Gruber wrote:

Long story short, a fast solution for the issue with EGLSetBlobFuncANDROID is to remove libraspberrypi-dev from your sysroot and do a full rebuild. There will be some changes to the configure results, so please review them - if they are relevant for you - before proceeding with your work.

And thanks to Andreas, the story can continue...