[tldistro] unexpected return value from verify_checksum: -5

[Karl Berry]

    Is there an option for the installer to install a specific TeX
    system "point in time" ?

No, unfortunately it's not that easy. The current installer cannot
install an arbitrarily old version of TL, in general.  

Old releases of TL (and the current release for that matter) are
available from the "historic" archive, tug.org/historic. For example,
the initial release for 2018 is:
  http://ftp.math.utah.edu/pub/tex/historic/systems/texlive/2018/
and the final release:
  http://ftp.math.utah.edu/pub/tex/historic/systems/texlive/2018/tlnet-final/

(there are several mirrors, also available by rsync, etc.)

I think it would work to download the install-tl-unx.tar.gz from
tlnet-final and then tell it to use that url as the repository to
install from. I've never tried it, though.

    Or by SVN revision number ?

The installer never has any interaction with svn. It uses only our
packaged archives (...tlnet/archive/...).

    Maybe install-tl --profile <PROFILE> should have an option --force
    to force start the install.

Just (re)move the file. That is safer (and easier) than adding an option
to override it.

    I had been hoping for a traditional numbering scheme,

I know. But as I wrote before, we're not going to turn install-tl into
its own independent software package with its own version numbers and
separate releases. Sorry.

Happy TeXing,
Karl