installer message about /usr/local/texlive/2019 not being writable

[jfbu]

Hi,

today I installed tlpretest on a pristine laptop under Ubuntu 16.04.
(yes I know this is perhaps a bit self-contradictory, not sure,
I inherited the laptop by a concourse of circumstances)

install-tl warned me about /usr/local/texlive/2019 not being writable
but in fact, of course, there wasn't even /usr/local/texlive to start with

maybe the message could be clearer? something like "/usr/local/texlive/2019
does not exist and admin rights are needed to create it"

I was left pondering if I should have used sudo install-tl, but I had
no time to test, so I created /usr/local/texlive/2019 and as is
my habit from other contexts gave my account the full rights to it
(not that I recommend this, but in the past it helped me manage
more easily various incursions into tlpkg etc... ; drawback
was particularly with Emacs/AUCTeX when it opened on compilation
errors style files, which could well end up modified by unwary
user).

Best,

Jean-François