Support use of environment variables in dot-f format?

[kevbroch]

My design.f file has something like +incdir+$DSNTOP/inc

So I kept getting the following message until I just replaced $DSNTOP with the full path.
Error: failed to include 'dsn_param.svh'

Here's Icarus Verilog doc description if that's useful.

[dalance]

Thank you for the request.
I added the support of variable with paren like Icarus at v0.2.19.

Now +incdir+$(DSNTOP)/inc or +incdir+${DSNTOP}/inc can be used.
I think +incdir+$DSNTOP/inc may be ambiguous and expect to use paren or brace.

[kevbroch]

Thank you for this feature and how quickly you did it.