Too many viminfo files

If you get the following error when closing Vim:

E929: Too many viminfo temp files, like /home/misha/.viminfa.tmp!
E138: Cannot write viminfo file /home/misha/.viminfa.tmp!

for some reason, you have too many viminfo temp files sitting in your home directory (or wherever else Vim is saying). I’m not sure why this happens, but deleting them clears the error:

$ rm /home/misha/.viminf*.tmp

See also

• https://vi.stackexchange.com/q/29283
• https://unix.stackexchange.com/q/134500