If Geany doesn't crash under the conditions above where it (via Scintilla) will probably successfully use libpthread
As said above, it doesn't even seem to be required (according to `ldd`)… so either gcc comes with a copy in libgcc or something, or it's implicit at some stage.
then it seems to me that the issue is a false positive from a pedantic warning option
`-Wl,-z,defs` isn't really a waning option, but rather a utility to verify you don't end up with unresolved symbols when actually loading the library. Here though, it seems to be some kind of a false positive indeed.
false positive […] that isn't an issue in real life
Yeah, it doesn't seem to have any adverse effect. Yet again, we *do* implicitly link to libpthread, and even so the dependency doesn't actually seem to be needed.