require-ing in irbrc shows warning "can't alias ls from irb_ls"

When one requires this gem in the irbrc file, you get a warning on irb startup, from ruby 2.7 onwards (tested in 2.7.1 and 3.0.0):

% irb -f -r'looksee'
irb: warn: can't alias ls from irb_ls.
irb(main):001:0>

If you require the gem after irb has finished loading, there is no issue.

% irb -f
irb(main):001:0> require 'looksee'
=> true
irb(main):002:0>

Main difference seems to be the result of show_source 'ls' (in REPL). For the startup (and command line) case it shows Looksee, otherwise irb/extend-command.rb.

Warning goes away if one adds Looksee.rename :_ls to irbrc ... but considering this happens for a straightforward installation, it seems like that should not be necessary. Would be great if require-ing looksee in irbrc and during REPL would behave the same way.

Probably relevant:

https://github.com/ruby/irb/pull/203
https://github.com/ruby/irb/commit/19b6c2060405583f9ac64db1d87f3bedfbe053f5#diff-707785dd86b785fc2279e00b12e4f4c316926e6e633de2bdd374d39b91f28ec5

oggy / looksee

require-ing in irbrc shows warning "can't alias ls from irb_ls" #56