🚀 go-pugleaf

GNU make 3.58 seems not to ignore trailing white space when a variable
definition is followed by a comment. For example, with the makefile

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

var = this is a test     # a variable definition, followed by a comment
show:
	@echo "'$(var)'"

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

the command "make show" produces the output

'this is a test     '


I was expecting 

'this is a test'

That's what the SUN version of make produces, and it's what page 53 of
the GNU make manual (Edition 0.26 Beta, 1/20/1990) seems to suggest: 
"A variable name may be any sequence [of] characters not containing `:', 
`#', `=', or leading or trailing whitespace." (The word "of" is missing
in the manual.)

Is this a bug, or a feature?