bug? limitation? by-design? :(

[Ian Ward]

Greetings,

I have been using GNU make to run image processing scripts for an image
gallery on a website and I've run into a problem with the way make
calculates dependencies.  When using pattern rules, the dependency
checker won't expand variables containing the pattern:

ht_long = master/big-long-hairy-toes.png
ht_opts = -gamma 0.9
ht_size = -geometry 800
sf_long = master/sunflower-slightly-open.png
sf_opts = -gamma 1.3
sf_size = -geometry 600
...

pics = ht sf ...

## This dep-pattern doesn't work
${pics:=.jpg} : %.jpg : ${%_long}
        /usr/bin/convert ${$*_opts} ${$*_size} ${$*_long} $@



I've tried using function calls etc, but nothing will let me say "look
for the dependency in the variable called <pattern>_long".

Is switchin to some other makefile generating language my only solution?

 -Ian Ward