sgasho

### Summary so far The choices are * close this PR * make error message more detailed * make this feature as an opt-in * else

@wsmoses cc: @ZuseZ4 Is this C++ code appropriate for reproducing the error? LLVM: 21.1.5 ```c++ #include "llvm/AsmParser/Parser.h" #include "llvm/Passes/PassBuilder.h" #include "llvm/Support/InitLLVM.h" extern "C" void registerEnzymeAndPassPipeline(llvm::PassBuilder &PB, bool augment); static auto...

c.f. I mainly looked around LLVMRustOptimize(It's in compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp in the rust codebase) in my PR([feat: dlopen Enzyme rust-lang/rust#149271](https://github.com/rust-lang/rust/pull/149271)) and then extracted core logic into c++ reproducer enzyme_fn = registerEnzymeAndPassPipeline and...

> Can you print the registered passes on Enzyme before & after calling registerEnzymeAndPassPipeline on your branch? The outputs I got are not so similar to the above one, but...

Note: What I recognize so far. 1. Tests pass when I register DominatorTreeAnalysys & LoopAnalysis to FAM at PreProcessCache::PreProcessCache 2. DominatorTreeAnalysys & LoopAnalysis do exist at PassRegistry.def 3. Error occurs...

Thanks for the hints. I checked using the following steps. anything wrong with them? 1. ./x build --stage 1 library/std 2. `cargo new` at another location 3. copied and pasted...

Ok, thanks! I'll check about step3 and 4 tomorrow

I found some bad lock operations in rust implementation in my pr caused deadlock and triggered "This analysis pass was not registered prior to being queried" errorr. I fixed it...