This was changed some time ago (https://google.github.io/oss-fuzz/getting-started/new-project-guide/) but the build didn't fail as there is a fallback mechanism. The main advantage of the new approach is that for libFuzzer this produces more performant binaries (as `$LIB_FUZZING_ENGINE` expands into `-fsanitize=fuzzer`, which links libFuzzer from the compiler-rt, allowing better optimization tricks).
I'm also experimenting with dataflow (https://github.com/google/oss-fuzz/issues/1632) on your project, and the dataflow config doesn't have a fallback (as it's a new configuration), therefore I'm proposing a change to migrate from `-lFuzzingEngine` to `$LIB_FUZZING_ENGINE`.
Navidem
Even Rouault
Max Moroz