Linux: O3DE fails to build due to "'elementName' set but not used" error

[LB-KacperBieniek]

Describe the bug Attempting to build Source configuration engine fails with an error:

gpc-94302@GPC-94302:~/o3de$ sudo cmake --build build/linux --target Editor --config profile -j 8
[5/767] Building CXX object Code/Frame...rk.dir/profile/Unity/unity_8_cxx.cxx.o
FAILED: Code/Framework/AzFramework/CMakeFiles/AzFramework.dir/profile/Unity/unity_8_cxx.cxx.o 
/usr/bin/clang++-14 -DAZ_BUILD_CONFIGURATION_TYPE=\"profile\" -DAZ_ENABLE_DEBUG_TOOLS -DAZ_ENABLE_TRACING -DAZ_PROFILE_BUILD -DLINUX -DLINUX64 -DNDEBUG -DPAL_TRAIT_LINUX_WINDOW_MANAGER_XCB -D_FORTIFY_SOURCE=2 -D_HAS_EXCEPTIONS=0 -D_PROFILE -D__linux__ -DCMAKE_INTDIR=\"profile\" -I/home/gpc-94302/o3de/Code/Framework/AzFramework/. -I/home/gpc-94302/o3de/Code/Framework/AzFramework/Platform/Linux -I/home/gpc-94302/o3de/Code/Framework/AzFramework/Platform/Common -I/home/gpc-94302/o3de/Code/Framework/AzFramework/Platform/Common/Xcb -I/home/gpc-94302/o3de/Code/Framework/AzCore/. -I/home/gpc-94302/o3de/Code/Framework/AzCore/Platform/Linux -I/home/gpc-94302/o3de/Code/Framework/AzCore/Platform/Common -I/home/gpc-94302/o3de/Code/Framework/AzNetworking/. -I/home/gpc-94302/o3de/Code/Framework/AzNetworking/Platform/Common -I/home/gpc-94302/o3de/Code/Framework/AzNetworking/Platform/Linux -I/home/gpc-94302/o3de/build/linux/Code/Framework/AzNetworking/Azcg/Generated/AzNetworking -isystem /home/gpc-94302/o3de-packages/packages/Lua-5.4.4-rev1-linux/Lua/include -isystem /home/gpc-94302/o3de-packages/packages/RapidJSON-1.1.0-rev1-multiplatform/RapidJSON/include -isystem /home/gpc-94302/o3de-packages/packages/RapidXML-1.13-rev1-multiplatform/RapidXML/include -isystem /home/gpc-94302/o3de-packages/packages/zlib-1.2.11-rev5-linux/zlib/include -isystem /home/gpc-94302/o3de-packages/packages/cityhash-1.1-multiplatform/cityhash/src -isystem /home/gpc-94302/o3de-packages/packages/lz4-1.9.4-rev2-linux/lz4/include -fno-exceptions -fvisibility=hidden -fvisibility-inlines-hidden -Wall -Werror -Wno-inconsistent-missing-override -Wrange-loop-analysis -Wno-unknown-warning-option -Wno-parentheses -Wno-reorder -Wno-switch -Wno-undefined-var-template -msse4.1  -O2 -g -fstack-protector-all -fstack-check -fPIC -std=c++17 -MD -MT Code/Framework/AzFramework/CMakeFiles/AzFramework.dir/profile/Unity/unity_8_cxx.cxx.o -MF Code/Framework/AzFramework/CMakeFiles/AzFramework.dir/profile/Unity/unity_8_cxx.cxx.o.d -o Code/Framework/AzFramework/CMakeFiles/AzFramework.dir/profile/Unity/unity_8_cxx.cxx.o -c /home/gpc-94302/o3de/build/linux/Code/Framework/AzFramework/CMakeFiles/AzFramework.dir/Unity/unity_8_cxx.cxx
In file included from /home/gpc-94302/o3de/build/linux/Code/Framework/AzFramework/CMakeFiles/AzFramework.dir/Unity/unity_8_cxx.cxx:3:
/home/gpc-94302/o3de/Code/Framework/AzFramework/AzFramework/DocumentPropertyEditor/Reflection/LegacyReflectionBridge.cpp:702:33: error: variable 'elementName' set but not used [-Werror,-Wunused-but-set-variable]
                    const char* elementName = "";
                                ^
1 error generated.
[12/767] Building CXX object Code/Fram...rk.dir/profile/Unity/unity_2_cxx.cxx.o
ninja: build stopped: subcommand failed.

Adding [[maybe_unused]] to const char* elementName = ""; fixes this issue: o3de/Code/Framework/AzFramework/AzFramework/DocumentPropertyEditor/Reflection/LegacyReflectionBridge.cpp: const char* elementName = ""; -> [[maybe_unused]] const char* elementName = "";

This issue occurred on Ubuntu 22.04.2 LTS, but did not occur on Ubuntu 20.04.4 LTS. Here is a similar issue found and resolved recently: https://github.com/o3de/o3de/issues/16263

Steps to reproduce Steps to reproduce the behavior:

1. Delete all of the files left after earlier O3DE installations/builds if present.
2. Clone, configure, and build O3DE (Source configuration).

Expected behavior Engine is built.

Actual behavior Engine build fails at the start, after successful clone and configuration.

Found in Branch Development (e4ed834)

Commit ID from o3de/o3de Repository e4ed834

Desktop/Device:

• Device: PC
• OS: Linux
• Version: Ubuntu 22.04.2 LTS
• CPU: Ryzen 5600H
• GPU: NVidia RTX 3070
• Memory: 16GB

[AMZN-daimini]

Likely my bad, will have a fix up ASAP :)

[AMZN-daimini]

Issue should be solved now that this change has been submitted, which removed the offending lines: https://github.com/o3de/o3de/pull/16290

[LB-KacperBieniek]

Issue verified as fixed on Development (bc68edc).