On Fri, Mar 03, 2023 at 05:46:15PM +0000, Simon McVittie wrote: > I've cut down what I think is the root cause of this compile failure to > a more minimal bug report: see #1032317.
That's super helpful, thanks :) Spoiler alert: I have a suspicion on the root cause, I'll follow up there. > I don't think this is *really* a regression, because in the version in > bookworm, the autopkgtest didn't exercise compilation of C++ into > WebAssembly at all. This statement strictly speaking is true, but applies only if you look at LLVM 15 in isolation. It *is* a regression, in the sense that this works with llvm-toolchain-14, where the WebAssembly work was first pushed, today, in both bookworm and sid. For example, retracing your steps in #1032317 with s/15/14/ does not result into a failure. > If I understand correctly, when compared with bookworm, the version in > sid adds a new feature (the necessary -dev packages for compiling C++ into > WebAssembly) and also adds a smoke-test for that feature, but the feature > doesn't yet work as intended. Is that accurate? Kind of -- again, strictly speaking, true for libc++-15-dev-wasm32. However, there is a metapackage, libc++-dev-wasm32, which Depends on the default implementation, which is libc++-14-dev-wasm32 right now. That metapackage has at least one notable reverse B-D, firefox, using it to build certain security/sandboxing features (RLBox[1], AIUI). That is to say, this feature works (w/ 14) and does very useful things today. it (seemingly) broke when it was ported to llvm-toolchain-15, which src:firefox does not depend on directly. 1: https://rlbox.dev/ Regards, Faidon
