How use DapStepOver etc commands in dapview window ?

[asadzman]

DapStepOver produces error

/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:448: Vim:E1513: Cannot switch buffer. 'winfixbuf' is enabled

[igorlfs]

Hello,

This happens because of nvim-dap's internal switchbuf setting (which defaults to your own config's value). In the likely case that you haven't set this up, the default uselast is used. That means that, strictly, only the last window can be used to show the buffer after a "step over" (or similar actions). However, nvim-dap does not properly handle windows with winfixbuf (a setting to "glue" a buffer to a window), which nvim-dap-view uses.

The FAQ contains a slightly outdated question mentioning this. Outdated because it describes the behavior prior to winfixbuf being enabled for nvim-dap-view windows, which was the full-on "overriding" of the window with uselast (which wasn't great either). Despite the question being outdated in this sense, its advice still holds: you can override nvim-dap's switchbuf setting (the recommendation from the FAQ is what I, personally, use).

This could be fixed on nvim-dap's side so that it'd ignore windows with winfixbuf (it's what nvim does internally, and it's also what nvim-dap-view does with its own switchbuf). However, nvim-dap's switchbuf "policy" is slightly different from the other cases: if no eligible window is found, it straight up refuses to show the buffer, with a message mentioning that

`switchbuf` setting prevented jump to location

Which means that if winfixbuf windows were ignored, instead of getting an error, you'd still get a warning, without a proper "jump".

As I mentioned, you can get around it by setting nvim-dap's switchbuf, which is fine if you just wanna "solve the problem for yourself". But if you care to "solve the problem for everyone else", my recommendation is to open an issue on nvim-dap's repo, explaining the situation. The way I see it, there are 2 alternatives; both are breaking:

1. Keeping the default switchbuf as nvim's default (i.e., uselast for most users), but introducing an "internal" fallback (i.e., always creating a top-level split). winfixbuf windows would be ignored, so the fallback would be more "commonly" used. This is consistent with nvim's behavior.
2. Switching the default switchbuf to an option that already includes a fallback. For instance, with uselast,newtab, a new tab can always be created. Ignoring winfixbuf windows remains a nice idea (since otherwise newtab may not trigger).

I kinda dislike both options, but I think the first one sucks less. You'd have to ask nvim-dap's maintainer what they think.

(sorry for the long answer, there's a surprising amount of nuance here)

(note: eventually I'll update the FAQ)

[asadzman]

Thanks for the quick reply :). By grepping the nvim-dap's author mfussenegger's config, I find he himself uses

  dap.defaults.fallback.switchbuf = "usevisible,usetab,uselast"

So I will be using that for now to keep it working 😅. As nvim being my first text editor and nvim-dap being my first debugger experience, I kinda scared to go too much into it. Atleast for now.

Btw it has been quite some pleasant experience using dap-view