Vim's default configuration presents significant debugging challenges due to its minimalistic design. While plugins substantially enhance Vim's capabilities, they can introduce complex error scenarios that require systematic troubleshooting techniques. This guide provides a structured approach to diagnosing and resolving Vim-related issues.
Error Message Management
Vim's error messages are transient and may disappear after a key press. To inspect recent errors:
:echo errmsg
In normal mode, use :messages to view all historical messages. For persistent debugging, capture messages in a new buffer:
:vnew | put=execute('messages')
Stack Trace Analysis
Complex errors often manifest as stack traces. The following example illustrates how to interpret such messages:
Error detected while processing function <SNR>163_on_exit_vim[15]..1:
line 1:
E687: Less targets than List items
The <SNR>163 and [15] components indicate that the 15 line in 163rd script triggered the error. Locate the responsible script using:
:vnew | put=execute('scriptnames')
The output may look like this:
163: ~/.vim/plugged/vim-gitgutter/autoload/gitgutter/async.vim
Navigate to the script file with gf on the path. Then inspect the function at the specified line (e.g., 15j).
Debugging Workflow
Once the error location is identified, execute targeted debugging:
debug echo expand('%:h')
or in neovim use:
vim.cmd(":debug echo expand('%:h')")
This command enables interactive debugging with the following control commands:
| Command | Action |
|---|---|
step | Execute command but step into functions |
next | Execute command but step over functions |
cont | Continue execution until next breakpoint |
quit | Stop execution immediately |
interrupt | Force pause until next command |
finish | Continue until current script/function completes |
breakadd/breakdel | Manage breakpoints with positional arguments |
Breakpoints locations can specify as follows:
- here: Current position
- file [line] [file]: Exact line in a file
- func [line] [function]: Line in a specific function
*for all breakpoints (used only for breakdel).
Logging Capabilities
Vim includes built-in logging through verbose mode:
vim -V9 myVim.log
This command starts Vim in maximum verbosity, writing detailed logs to myVim.log. Comprehensive documentation exists in Vim's native help system and relevant Stack Exchange discussions.