make/unit-tests/varname-dot-make-level.exp

level 1: variable 0, env 1
level 2: variable 1, env 2
level 3: variable 2, env 3
make: Cannot override read-only global variable ".MAKE.LEVEL.ENV" with a command line variable
make: Fatal errors encountered -- cannot continue
make: stopped in unit-tests
*** Error code 1 (continuing)
`all' not remade because of errors.

Stop.
make: stopped making "all" in unit-tests
exit status 1