Compile source code into executable

I need an executable from this C++ project so QA can smoke-test on Friday. Build the main target from the src folder, include the third_party libs in libs/, produce a single binary named game_server, and stop if any object file is missing. Verify the binary starts and prints its version string before you hand it back to me.

Before I hand this build to QA, make it easy for them to verify: surface the final binary size and build time at the top, list any non-standard compiler flags used, and flag any warnings that were not treated as errors. If link steps pulled in multiple lib versions, call that out and suggest the smallest set of libs to reproduce locally.

I ran a clean build of the main target and the link step failed with undefined reference to Player::serialize, and I already confirmed the .o for player.cpp exists. The team lead expects a working binary by Friday and I can't slow the pipeline. I haven't inspected the offending symbols across static libs. What is the most likely cause and the quickest, low-risk next step to get back to a linkable build?

Across several projects we repeatedly hit link errors late in the cycle and lose half a day chasing missing symbols or duplicate libraries. I handle builds, deps and release artifacts and this eats scheduling and credibility with QA. Which habit should I change in our workflow to prevent these recurring link-time failures and make builds predictable?