Computed variables and .VARIABLES

[Martin d'Anjou]

Hi,

I try to fish variable names out of .VARIABLES and then use their values, 
but it does not work:

var_t1=foo
var_t2=bar
not_a_var=boo

s=$(filter var_%,$(.VARIABLES))
$(warning $s)
$(warning $($s))
$(warning $($($s)))

I want the warnings to print the values foo and bar. I do not want this to 
happen inside the command being carried out because I wish to use these 
computed names as prerequisites:

all: $($s)

foo:
        @echo building foo

bar:
        @echo building bar

Is this possible?

Thanks!
Martin d'Anjou