[racket] Issue with "raco pkg install -u"

Why raco requires write permissions to /usr?

--> raco pkg install --scope user frog
The following packages are listed as dependencies, but are not currently 
installed:
         markdown rackjure
Would you like to install them via your package indices? [Yn]
raco setup: version: 5.3.5 [3m]
raco setup: variants: 3m
raco setup: main collects: /usr/local/lib/racket/collects
raco setup: collects paths:
raco setup:   /home/juanfra/.racket/5.3.5/collects
raco setup:   /usr/local/lib/racket/collects
raco setup: --- pre-installing collections ---
raco setup: --- compiling collections ---
raco setup: making: /home/juanfra/.racket/5.3.5/pkgs/installed/frog/example
raco setup: making: 
/home/juanfra/.racket/5.3.5/pkgs/installed/frog/example/_src
raco setup: making: 
/home/juanfra/.racket/5.3.5/pkgs/installed/frog/example/_src/posts
raco setup: making: 
/home/juanfra/.racket/5.3.5/pkgs/installed/frog/example/_src/subdir
raco setup: making: 
/home/juanfra/.racket/5.3.5/pkgs/installed/frog/example/css
raco setup: making: 
/home/juanfra/.racket/5.3.5/pkgs/installed/frog/example/img
raco setup: making: 
/home/juanfra/.racket/5.3.5/pkgs/installed/frog/example/js
raco setup: making: /home/juanfra/.racket/5.3.5/pkgs/installed/frog/frog
raco setup:  in /home/juanfra/.racket/5.3.5/pkgs/installed/frog/frog/
raco setup:  in 
/home/juanfra/.racket/5.3.5/pkgs/installed/rackjure/rackjure/
raco setup:  in 
/home/juanfra/.racket/5.3.5/pkgs/installed/rackjure/rackjure/lang/
raco setup:  in 
/home/juanfra/.racket/5.3.5/pkgs/installed/markdown/markdown/ 
                  [57/727]
raco setup:  in /home/juanfra/.racket/5.3.5/pkgs/installed/frog/
raco setup: making: 
/home/juanfra/.racket/5.3.5/pkgs/installed/markdown/markdown
raco setup:  in 
/home/juanfra/.racket/5.3.5/pkgs/installed/markdown/markdown/
raco setup: making: 
/home/juanfra/.racket/5.3.5/pkgs/installed/markdown/markdown/test
raco setup: making: 
/home/juanfra/.racket/5.3.5/pkgs/installed/rackjure/rackjure
raco setup:  in 
/home/juanfra/.racket/5.3.5/pkgs/installed/rackjure/rackjure/
raco setup: making: 
/home/juanfra/.racket/5.3.5/pkgs/installed/rackjure/rackjure/lang
raco setup: making: scribblings/main/user
raco setup:  in scribblings/main/private
open-output-file: cannot open output file
   path: 
/usr/local/lib/racket/collects/scribblings/main/private/compiled/make-search_rkt.zo
   system error: Permission denied; errno=13
raco setup: --- updating info-domain tables ---
raco setup: updating: <user>/info-domain/compiled/cache.rktd
raco setup: --- creating launchers ---
raco setup: --- building documentation ---
raco setup: --- installing collections ---
raco setup: --- post-installing collections ---
raco setup:
raco setup: error: during making for scribblings/main/user
raco setup:   open-output-file: cannot open output file
raco setup:     path: 
/usr/local/lib/racket/collects/scribblings/main/private/compiled/make-search_rkt.zo
raco setup:     system error: Permission denied; errno=13