Debugging Rust with vim and neovim (in Linux)

🔗Step 1

Run :packadd termdebug inside vim/nvim. This is not some third party package manager, packadd is built into vim.

This has to be done for every instance, so if you want this to always be enabled then add this to your vimrc.

Also to use rust-gdb rather than standard gdb set let g:termdebugger="rust-gdb".

🔗Step 2

Build your project (so you have something to debug in ./target/debug/<your project>)

🔗Step 3

From within vim/nvim run :Termdebug target/debug/<your project>. This will start gdb.

Now you can set a breakpoint with :Break and finally run the code with :Run.

🔗Commands

• :Break sets a breakpoint where the cursor is
• :Run starts the debugger
• :Clear removes the breakpoint under the cursor
• :Over steps over the current line
• :Step steps into the current line
• :Continue to continue execution
• :Evaluate to execute selected code or code under cursor

For more information see :help Termdebug inside vim/nvim.

Note To see the value of the variable under the cursor: K (shift + k) by default.

🔗GDB dashboard

If you want to use gdb dashboard (this is useful as it lets you see the locals all the time) you can get this from https://github.com/cyrus-and/gdb-dashboard/ (check your package manager if you are on Linux as it might exist there as well).

Create $XDG_CONFIG/gdb-dashboard/init and add the follow lines:

dashboard -layout variables
dashboard variables -style compact False

A hack: Somewhere around line 527 (at the time of writing) there is an if-statement that checks if you are running inside gdb or printing to a file.

if fs is not gdb or clear_screen:
    buf += Dashboard.clear_screen()

By removing the if and changing this to

buf += Dashboard.clear_screen()

the locals will stay on top in the NeoVim terminal (otherwise they will keep scrolling the window).