apt-src cannot build

[Marcus Sundman <sundman@iki.fi>]

I do the following (irrelevant output omitted):
----8<--------------------------------------------------------
/usr/src/tmp$ apt-src install foo
/usr/src/tmp$ cd foo-version
/usr/src/tmp/foo-version$ apt-src build foo
E: Not installed
/usr/src/tmp/foo-version$ 
---->8--------------------------------------------------------

Any idea what might be wrong?


- Marcus Sundman