opam switch create 4.07.0 not working

[AjayAB]

I installed opam:
user@dell-2017:~$ opam --version
2.0.8

ran opam init
but the next two commands didn't work
user@dell-2017:~$opam switch create 4.07.0
[ERROR] No compiler matching '4.07.0' found, use 'opam switch list-available' to see what is available, or use '--packages' to select packages explicitly.
user@dell-2017:~$ opam install dune core lwt re color sexp_pretty uutf lwt_ppx uuseg notty [ERROR] No package named dune found. [ERROR] No package named core found. [ERROR] No package named re found. [ERROR] No package named color found. [ERROR] No package named sexp_pretty found. [ERROR] No package named uutf found. [ERROR] No package named lwt_ppx found. [ERROR] No package named uuseg found. [ERROR] No package named notty found.

[alexozer]

What's your Linux version? uname -a

[AjayAB]

hi,
I was on Ubuntu 18.04 . I just distrohopped into arch .
[ajay@dellarch ~]$ uname --a
Linux dellarch 5.10.25-1-lts #1 SMP Sat, 20 Mar 2021 19:37:44 +0000 x86_64 GNU/Linux
in arch , opam switch create 4.07.0 worked.
But dune build didn't work.
[ajay@dellarch ~]$ cd flitter/
[ajay@dellarch flitter]$ dune build
bash: dune: command not found
[ajay@dellarch flitter]$ opam dune build
[ERROR] dune is not a known command or plugin (package dune.2.8.4 does not have the 'plugin' flag set).
[ajay@dellarch flitter]$ ls
LICENSE bin dune-project flitter.install src
README.md doc examples flitter.opam
[ajay@dellarch flitter]$ dune build flitter.opam
bash: dune: command not found
[ajay@dellarch flitter]$ opam dune build flitter.opam
[ERROR] dune is not a known command or plugin (package dune.2.8.4 does not have the 'plugin' flag set).
[ajay@dellarch flitter]$ opam dune build flitter.install
[ERROR] dune is not a known command or plugin (package dune.2.8.4 does not have the 'plugin' flag set).
I tried all of that ^ , but it didn't work.

[burbruee]

Did you do

eval $(opam env) ?

After that, dune should work.

[xRasea]

Could you add this to the readme? Worked for me. Thanks.