assertion failure with template instantiation of forward reference class

[bearophile]

comco:

> Looks like a bug?

This is what DMD 2.061alpha prints, it doesn't crash:

...\dmd2\src\phobos\std\range.d(603): Error: static assert  
"Cannot put a string into a LockingTextWriter"
...\dmd2\src\phobos\std\format.d(2349):        instantiated from 
here: put!(LockingTextWriter, string)
...\dmd2\src\phobos\std\format.d(2782):        instantiated from 
here: formatValue!(LockingTextWriter, TypeInfo_Class, char)
...\dmd2\src\phobos\std\format.d(415):        instantiated from 
here: formatGeneric!(LockingTextWriter, TypeInfo_Class, char)
...\dmd2\src\phobos\std\stdio.d(712):        ... (1 
instantiations, -v to show) ...
...\dmd2\src\phobos\std\stdio.d(1618):        instantiated from 
here: write!(TypeInfo_Class,char)
test.d(5):        instantiated from here: writeln!(TypeInfo_Class)

Bye,
bearophile