[tex-live] TL'16 pretest luatex fails with

[Michael]

- I'm on Linux (x86_64).
- I've installed only "collection-basic" and "collection-luatex".
- My luatex of TeXLive 2015 works fine.
- I've tried rebuilding the format files by running `fmtutil-sys --all`
  with appropriate priveleges but I get the error

	"fmtutil [ERROR]: running `luajittex -ini   -jobname=luajittex
		-progname=luajittex luatex.ini </dev/null' return status 1
	fmtutil [ERROR]: `luajittex -ini   -jobname=luajittex
		-progname=luajittex luatex.ini </dev/null' failed
		(no luajittex.fmt)".

Though I've located the file "luajittex.fmt" at
$TEXMFSYSVAR/web2c/luajittex/luajittex.fmt.

Help would be appreciated.

Michael