= Startup time =

vim --startuptime vimstartup.txt

Then open this file, and you should see a heading and a list of timing messages.
You could also try piping the output of the file through "sort -k 2" to easily find the slowest sourced scripts. (cat vimstartup.txt | sort -k 2)

Btw, using :help slow-start will show you Vim's built-in guidance on startup performance. If you're trying to improve Vim startup process, this might be a good start.


= Debug Errors =

Check previous error message with :messages