I don't recall. Sometimes doing a full rebuilt takes more a while, so my process goes something like this: 1) build with "-O0 -ggdb" 2) In a debug session, no

I don't recall. Sometimes doing a full rebuilt takes more a while, so my process goes something like this: 1) build with "-O0 -ggdb" 2) In a debug session, notice that a variable I want to inspect has supposedly been optimized away. Get extremely frustrated. 3) Rebuild with every debug-friendly flag I can conceive of "-O0 -ggdb -fno-inline -gdwarf-4 -fno-omit-frame-pointer ..." 4) IIRC, step 3 usually (but not always?) addresses the issue. But long story short, I don't think I've ever pinned down the minimal requirements for avoiding the issue. Usually when I encounter this, I have bigger issues to deal with.