Error: identifier 'string' is not defined

[Byron Heads]

After upgrading an ubuntu machine from 2.047 to 2.048 I am getting an 
error:

/usr/include/d/dmd/phobos/std/traits.d(25): Error: identifier 'string' is 
not defined

I doesn't matter what I compile.

I added
alias immutable(char[]) string to traits.d

Then I get the following error.

/usr/include/d/dmd/phobos/std/metastrings.d(131): Error: identifier 
'string' is not defined

Where is string defined, and why is it not in the deb installer?

Sorry if someone has already posted this, but I did a google site search 
and came up with nothing on D2.

-B