libclang5 vs libclang4? (and anecdotal evidence of a potential deadlock during startup)

[René J.V. Bertin]

This should be more on-topic: is there any advantage to using libclang5 instead of libclang4 for the kdev-clang parser?

FWIW, my previous KDevelop build was with clang 4, a rebuild using exactly the same options (-Ofast -g) definitely feels more sluggish, as if loading times are somewhat longer.

I also ran into a curious deadlock during startup, apparently while loading the patchreview plugin and related to both libpurpose and the recent change to KTextEditor that sets QV4_FORCE_INTERPRETER=1 for Qt versions < 5.9.1 . I'm mentioning it here and not on BKO because I can no longer reproduce it (my first priority was to find a workaround). I do know it was a proper deadlock, i.e. an endless wait for a mutex or semaphore; it was accompanied by TWO Qt warnings about QML animations being slow because of JIT deactivation, instead of a single such warning.
I can file a BKO report if this rings any bells (or if you think I should anyway).

R.