[Agda] installing 2.6.2

[mechvel at scico.botik.ru]

Please,
help to install Agda-2.6.2.

It is on Ubuntu Linux 18.04, ghc-8.8.3, cabal-3.6.2.0.

I un-archivate the source and command

  $ cd 2.6.2
  $ cabal update

  Downloading the latest package list from hackage.haskell.org
  Package list of hackage.haskell.org is up to date at index-state 
2021-12-07T09:32:17Z

  $ cabal install Agda

  cabal: sdist of Agda-2.6.2: filepath wildcard 'doc/user-manual.pdf' 
does not
  match any files.

?

------
Sergei