[tex-live] using luatex53 - format not found

[Ulrike Fischer]

I'm trying to setup a lualatex35 format to be able to run some tests
on luaotfload with it. I'm on windows 10.

I do *not* want to completly switch to it and using the format with
luatex53 -fmt=lualatex53 ... is fine for me. 

I added an entry to a local fmtutil.cnf

    lualatex53 luatex53 language.dat,language.dat.lua lualatex.ini

and created the format in texmf-local/texmf-var/web2c/luatex53/
with 
    fmtutil-sys -byfmt=lualatex53

This worked fine and kpsewhich -engine=luatex53 lualatex.fmt finds
the format. 

But I can't use it. 

luatex53 --fmt=lualatex53  test-utf8

starts a new (successfull) format creation and then ends with:

warning  (pdf backend): no pages of output.
Transcript written on lualatex53.log.
fmtutil [INFO]:
c:/users/nililand-surface/.texlive2018/texmf-var/web2c/luatex53/lualatex53.fmt
installed.
fmtutil [INFO]: Disabled formats: 6
fmtutil [INFO]: Successfully rebuilt formats: 1
fmtutil [INFO]: Not selected formats: 44
fmtutil [INFO]: Total formats: 51
fmtutil [INFO]: exiting with status 0
I can't find the format file `lualatex53.fmt'!


When I copy the format to the current directory everything works as
expected

What is happening here? Why can't luatex53 find the format in the
luatex53 folder when kpsewhich can? 

-- 
Ulrike Fischer 
https://www.troubleshooting-tex.de/