The [HACKING](https://github.com/geany/geany/blob/master/HACKING) file has this:
> Before the 1.0 release series, the ABI can change when necessary, and even the API can change. Obviously Geany has long switched to 1.x versions. Does this text still apply? -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/geany/geany/issues/1475
