Handling of ENV options

[Kalev Soikonen]

I got hit by weird behavior while installing some package (as root). In shell
environment, the variable GZIP=-9 is set and exported. The package Makefile
contains something like this:

GZIP = /bin/gzip

target: dep
        somecmd $< | $(GZIP) -9 > $@

Apparently, gmake exports the variables that were exported in the first place,
thus gzip is invoked with "GZIP=/bin/gzip" in its env. The result being zero-
length target _and_ gzip executable compressed into gzip.gz.
Now this can be seen as outrageously funny, but I wonder...